بالاخره موفق شدم
کد رو اینجا قرار میدم شاید مابقی دوستان هم استفاده کردند
Dim myHttpWReq As HttpWebRequest = _
CType(WebRequest.Create("http://www.example.com/text1.txt"), HttpWebRequest)
Dim myHttpWResp As HttpWebResponse = _
CType(myHttpWReq.GetResponse(), HttpWebResponse)
Dim receiveStream As Stream = myHttpWResp.GetResponseStream()
Dim encode As Encoding = System.Text.Encoding.GetEncoding("utf-8")
Dim readStream As New StreamReader(receiveStream, encode)
Dim str3 As String = readStream.ReadToEnd
readStream.Close()
myHttpWResp.Close()