Say the rows you want to hide and unhide are 5:10. Put a macro like this in a module
Sub HideUnhide()
Rows("5:10").Select
If Selection.EntireRow.Hidden = False Then
Selection.EntireRow.Hidden = True
Else
Selection.EntireRow.Hidden = False
End If
Range("$A$1").Select
End Sub
Assign this macro to your CheckBox