i have installed plasma-widget-window-menubar,with all his dependencies,but it do not shows completely,i have linuxmint 12 kde 64bits,i want the unity style in kde.

image from my desktop:

http://img690.imageshack.us/img690/4048/snapshot1uv.png

Have you tried with applications other than Dolphin or Firefox, such as KWrite or Kontact?

For Dolphin, try pressing Ctrl + M to get it to switch into menu bar enabled mode.