程序代码：

Private Sub Command1_Click()
Dim s As String, t As String, i&
s = ",,"
With List1
For i = 0 To .ListCount - 1
s = s & .List(i) & ",,"
Next
End With

With List2
For i = 0 To .ListCount - 1
If InStr(s, ",," & .List(i) & ",,") Then t = t & "," & .List(i)
Next
End With
t = IIf(Len(t) > 1, Mid(t, 2), "无重复")
MsgBox t
End Sub