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=1 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