Trying to select only one chart rather than all charts on spreadsheet - Help VBA coding

Hi and welcome to the forum.

1) Please read our http://www.excelforum.com/forum-rule...rum-rules.html and observe them. Now edit your post using code tags.

2) In presented code, VBA loops through all chartobjects. If you want to use just one - use it's number or name or somehow select just one.

for instance try:

Sub MarginChart()
Dim Cht As ChartObject
set Cht = ActiveSheet.ChartObjects(1)
Cht.Chart.ChartArea.AutoScaleFont = False
Cht.Height = Application.CentimetersToPoints(3.57)
Cht.Width = Application.CentimetersToPoints(5.81)
cht.Axes(xlValue).TickLabels.Font.Size = 7
cht.Axes(xlCategory).TickLabels.Font.Size = 7
cht.ChartArea.Border.LineStyle = xlNone
set cht = nothing
End Sub

Please do what I suggested in p.1 above (editing+code tags).
Then note that problematic line comes from your code.