Sub CheckKeyPrimary()
    On Error GoTo CreateKeyError

    Dim cat    As New ADOX.Catalog
    Dim i      As Byte

    cat.ActiveConnection = "Provider='Microsoft.Jet.OLEDB.4.0';" & _
                           "Data Source='c:\mas.mdb';"

    With cat.Tables("品类")

        If .Keys.Count < 1 Then MsgBox "没有主键": Exit Sub
        For i = 0 To .Keys.Count - 1
            If .Keys.Item(0).Type = adKeyPrimary Then MsgBox "有主键": Exit Sub

        Next
        MsgBox "没有主键"
    End With

    'Clean up
    Set cat.ActiveConnection = Nothing
    Set cat = Nothing
    Exit Sub

CreateKeyError:
    Set cat = Nothing

    If Err <> 0 Then
        MsgBox Err.Source & "-->" & Err.Description, , "Error"
    End If

End Sub