dear xld,

many thanks for your advice.
Now i know why i kept getting error messages for the whole day.
I adopt another method which is now working for me
        For i = 2 To RowCount
            If Cells(i, 8).Value = "none" Then
                arraySize = arraySize + 1
            End If
        Next i
        ReDim myArray(arraySize - 1) As Variant
        n = 0
        For i = 2 To RowCount
            If Cells(i, 8).Value = "none" Then
                myArray(n) = Cells(i, 6).Value
                n = n + 1
            End If
        Next i
        FilteredData = myArray