我把昨天的代码改写成如下：还是那个错误呀！怎么办？？？？？？
<table border="1" cellpadding="0" cellspacing="0" width="90%" bordercolordark="#FFCC99" bordercolorlight="#FFCC99" style="border-collapse:collapse">
<%set rs=server.CreateObject("adodb.recordset")
rs.open "select second_class_name from big_class wherebig_class_name in (select big_class_name from big_class) order by id desc",conn,1,1
 do while not rs.eof %>
    <tr height="30"><td bgcolor="#eaeaea" valign="bottom" align="center"><%=trim(rs("big_class_name"))%> </td></tr>       
    <tr><td><%=trim(rs("second_class_name"))%></td></tr>
<% rs.movenext
    loop
rs.close
set rs=nothing%>                  
</table>

“ wherebig_class_name ”之间有空格的。

<table border="1" cellpadding="0" cellspacing="0" width="90%" bordercolordark="#FFCC99" bordercolorlight="#FFCC99" style="border-collapse:collapse">
<%set rs=server.CreateObject("adodb.recordset")
rs.open "select * from second_class where big_class_name in (select big_class_name from big_class) order by id desc",conn,1,1
 do while not rs.eof %>
    <tr height="30"><td bgcolor="#eaeaea" valign="bottom" align="center"><%=trim(rs("big_class_name"))%> </td></tr>       
    <tr><td><%=trim(rs("second_class_name"))%></td></tr>
<% rs.movenext
    loop
rs.close
set rs=nothing%>                  
</table>

这个没问题呀，楼主检查是否是字段或是数据库表的拼写错误，把ie缓存清空再运行程序试试

可能数据库连接出错，，或者rs字段写错，也就是数据库中根本就没有你的字段，，仔细找找

Server.ScriptTimeOut=500
实在不行把脚本超时时间进行更改。