My xubuntu's menu is very simple.
I've noticed that new xfce menu is much pretier with new theme as bellow
how can i make change to newer style?
Xfce uses GTK2 themes for customization. Check out http://gnome-look.org/index.php?xcontentmode=100&PHPSESSID=56eb14690452b50911b07b88ea68daab and http://xfce-look.org/index.php?xcontentmode=15x100x420&PHPSESSID=2680837881809694cad5e06bae10e01f for a huge collection of GTK2 themes. The two start menus in your screenshots differ by more than colors, these are different applets. The new menu applet (second screenshot) is called Whisker Menu, you can find it in the applet list of your Xfce panel.