So, just as the title, how can detect mouse move on every menu item on
my form? and I also know that which item the mouse is on. Can I use
something like SetWindowLong or anything else can do? Thank you

Hi Bruce.  You may find the following article helpful:

HOWTO: Display Descriptions of Menu Items When Highlighted
Article ID: Q185451
http://support.microsoft.com/support/kb/articles/q185/4/51.asp?FR=0

Here's another link:

Menu Status Messages - How to subclass a form and watch for menu items being clicked
so that you can provide a status/help message.
http://www.matthart.com/vbhelp/MENUSTAT.ZIP

'-------
galen

Use the MouseMove function for each object and for the form.  For example, I
use a menu of command buttons.  To animate them, I used the MouseMove
function for each of them.

Private Sub Form_MouseMove
Command1.FontBold = False
Command2.FontBold = False
End Sub

Private Sub Command1_MouseMove
Command1.FontBold = True
Command2.FontBold = False
End Sub

Private Sub Command2_MouseMove
Command1.FontBold = False
Command2.FontBold = True
End Sub

Of course, you can post whatever you want within each event.  I also use the
MouseMove to change text in the status bar at the bottom of my form:

Private Sub Command2_MouseMove
StatusBar1.Panels(1).Text = "Add new customer"

Hope this helps.