Code
<asp:datagrid id="DataGrid1" runat="server" width="100%"  AutoGenerateColumns="False"   >
                                        
                                        <Columns>
                                                  
                                                <asp:TemplateColumn HeaderText="aaaaaa element&lt;/td&gt;&lt;td rowspan=&quot;2&quot;&gt;proportion&lt;/td&gt; &lt;td rowspan=&quot;2&quot;&gt;Detailed rules&lt;/td&gt; &lt;td rowspan=&quot;2&quot;&gt;Behavior&lt;br&gt;examples&lt;/td&gt; &lt;td rowspan=&quot;2&quot;&gt;proportion&lt;/td&gt;&lt;td colspan=&quot;2&quot;&gt; Self&lt;br/&gt;evaluation&lt;/td&gt; &lt;td colspan=&quot;2&quot;&gt;Mgr&lt;br/&gt;evaluation&lt;/td&gt; &lt;td colspan=&quot;2&quot;&gt;Hr / Director&lt;br/&gt;evaluation&lt;/td&gt;&lt;/tr&gt;  &lt;tr&gt;&lt;td class='class1'&gt;score&lt;/td&gt;&lt;td&gt;Key&lt;br/&gt;case&lt;/td&gt;&lt;td class='class2'&gt;score&lt;/td&gt;&lt;td&gt;Key&lt;br/&gt;case&lt;/td&gt;&lt;td class='class3'&gt;score&lt;/td&gt;&lt;td&gt;Key&lt;br/&gt;case">
                                                    <HeaderStyle Width="18%"></HeaderStyle>
                                                     <ItemStyle Width="18%"  />
                                                    <ItemTemplate>
                                                   
                                                    </ItemTemplate>
                                                </asp:TemplateColumn>
                                                
                                                <asp:TemplateColumn HeaderText="asdfasfasdfa">
                                                         <HeaderStyle Width="9%"></HeaderStyle>
                                                           <ItemStyle Width="9%"  />
                                                            <ItemTemplate>
                                                        
                                                            </ItemTemplate>
                                                </asp:TemplateColumn>
                                                
                                                 <asp:TemplateColumn HeaderText="fghdfghdfhd rules">
                                                          <HeaderStyle Width="20%"></HeaderStyle>
                                                          <ItemStyle Width="20%"  />
                                                            <ItemTemplate>
                                                     
                                                            </ItemTemplate>
                                                </asp:TemplateColumn>
                                                
                                                
                                                 <asp:TemplateColumn HeaderText="sdfgsdfgsdfg sdfgsdf">
                                                          <HeaderStyle Width="9%"></HeaderStyle>
                                                          <ItemStyle Width="9%" HorizontalAlign="Center" />
                                                            <ItemTemplate>
                                                           
                                                            </ItemTemplate>
                                                </asp:TemplateColumn>
                                                
                                                
                                                <asp:TemplateColumn HeaderText="sdfgsdfgsd">
                                                          <HeaderStyle Width="9%"></HeaderStyle>
                                                            <ItemStyle Width="9%" />
                                                            <ItemTemplate>
                                                      
                                                                  
                                                            </ItemTemplate>
                                                </asp:TemplateColumn>
                                                
                                                 <asp:TemplateColumn HeaderText="asdfasdfasdf">
                                                            <HeaderStyle Width="7%"></HeaderStyle>
                                                             <ItemStyle Width="7%"  />
                                                            <ItemTemplate>
                                                                   </ItemTemplate>
                                                </asp:TemplateColumn>
                                                
                                                  <asp:TemplateColumn HeaderText="asdf asdfasdf">
                                                          <HeaderStyle Width="5%"></HeaderStyle>
                                                           <ItemStyle Width="5%"  HorizontalAlign="Center"/>
                                                            <ItemTemplate>
                                                             </ItemTemplate>
                                                </asp:TemplateColumn>
                                                
                                                
                                              <asp:TemplateColumn HeaderText="scasdfasdfore">
                                                           <HeaderStyle Width="6%"></HeaderStyle>
                                                             <ItemStyle Width="6%"  />
                                                            <ItemTemplate>
                                                             </ItemTemplate>
                                                </asp:TemplateColumn>
                                                
                                                  <asp:TemplateColumn HeaderText="asdf asdf">
                                                           <HeaderStyle Width="5%"></HeaderStyle>
                                                           <ItemStyle Width="5%"   HorizontalAlign="Center"/>
                                                            <ItemTemplate>
                                                             </ItemTemplate>
                                                </asp:TemplateColumn>
                                                
                                              <asp:TemplateColumn HeaderText="score">
                                                           <HeaderStyle Width="7%"></HeaderStyle>
                                                           <ItemStyle Width="7%"  />
                                                            <ItemTemplate>
                                                             </ItemTemplate>
                                                </asp:TemplateColumn>
                                                
                                                  <asp:TemplateColumn HeaderText="asdfasdfasd">
                                                           <HeaderStyle Width="6%"></HeaderStyle>
                                                           <ItemStyle Width="6%" HorizontalAlign="Center"/>
                                                            <ItemTemplate>
                                                             </ItemTemplate>
                                                </asp:TemplateColumn>
                                                
                                                
                                                <asp:BoundColumn DataField="ID" HeaderText="ID" Visible="False">
                                                              <HeaderStyle Width="10px"></HeaderStyle>
                                                </asp:BoundColumn>
                                                
                                                   <asp:BoundColumn DataField="RowFlag" HeaderText="RowFlag" Visible="False">
                                                              <HeaderStyle Width="10px"></HeaderStyle>
                                                </asp:BoundColumn>    
                                                
                                                          
                                                         
                                        </Columns>
                                        <PagerStyle HorizontalAlign="Left" ForeColor="#003399" BackColor="#99CCCC" Mode="NumericPages"></PagerStyle>
                                    </asp:datagrid>