Hi Andy. Thx for your wise suggestions. I managed to use all the code you sent including the part for running the code when changing the cells.

I'm not able to use it when the chart is in different datasheet though. I think the problem is in defining the variables MinValue & and Maxvalue as inputs you suggested in the rutine you sent. All the cells are in sheet1 and the chart is within the same book as chart sheet.

Sub AxisChange(Cht As Chart, MinValue, MaxValue)
    With Cht.Axes(xlValue)
        .MinimumScale = MinValue
        .MaximumScale = MaxValue
    End With
End Sub
How should I do that? Is there any modification in here?

Private Sub Worksheet_Change(ByVal Target As Range)

    If Not Intersect(Range("A1:A2"), Target) Is Nothing Then
        AxisChange ActiveSheet.ChartObjects(1).Chart, Range("A1").Value, Range("A2").Value
    End If
    
End Sub
Thx