nstall these packages:
apt-get install gnome-panel gnome-settings-daemon metacity nautilus gnome-terminal
Use this ~/.vnc/xstartup file:
#!/bin/sh export XKL_XMODMAP_DISABLE=
unset SESSION_MANAGER
unset DBUS_SESSION_BUS_ADDRESS [ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup
[ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
xsetroot -solid grey
vncconfig -iconic & gnome-panel &
gnome-settings-daemon &
metacity &
nautilus &
gnome-terminal &
轉自：http://askubuntu.com/questions/518041/unity-doesnt-work-on-vnc-server-under-14-04-lts