are you sure ASP:Label control has an InnerHtml property? the HtmlGenericControl has one, try the following (in C#):label1.Text = "<span style='color:red'>hello world</span>"; label2.InnerHtml = "<span style='color:green'>hello china</span>"; <ASP:Label id="label1" runat="server"></ASP:Label> <span id="label2" runat="server"></span>
label2.InnerHtml = "<span style='color:green'>hello china</span>";
<ASP:Label id="label1" runat="server"></ASP:Label>
<span id="label2" runat="server"></span>