试试改这段代码
http://msdn.microsoft.com/zh-cn/library/system.text.encoding.aspx
Dim url As String = Args(0)
Dim rqst As System.Net.HttpWebRequest = System.Net.HttpWebRequest.Create(url)
Dim rsps As System.Net.HttpWebResponse = rqst.GetResponse
Dim stm As System.IO.Stream = rsps.GetResponseStream()
rsps = Nothing
rqst = Nothing
Dim reader As New System.IO.StreamReader(stm, System.Text.Encoding.Unicode)
Dim strXML As String = reader.ReadToEnd
stm.Dispose()
msgbox(strXML)
Return strXML