Use code like the following
Sub HideRows()
Dim r&
for r = 1 to Sheet1.UsedRange.Rows.Count
select case Sheet1.cells(r,1).value
Case "aa","bb","cc"
Sheet1.Rows(r).Hidden=true
Case Else
Sheet1.Rows(r).Hidden=false
end select
Next r
End Sub

"Dennis Cheung" wrote:

i need to hide rows if a cell's content is aa or bb or cc. these contents
are located in column A.
can i do it by a marco?

dennis