The formation control for underactuated surface ships with 3 degree － of － freedom is investigated，and the shape tracking
controllers based on Leader /Follower method are developed． The ship is controlled respective，when the system received the shape-command．
The Leader tracked the shape-command directly，and the Followers tracked the designed trajectory，which is designed by the
shape-command and the state of the Leader． For the design of tracking control，firstly，reference tracking path and reference forward
speed are designed based on desired formation shape． Secondly，path tracking controller and speed tracking controller are constructed by
nonlinear control theory and Lyapunov theory． Finally，the shape tracking error of the follower is uniformly ultimately bounded． Numerical
simulations show the system can tracking any curves． The results validate the effectiveness of proposed controller．