An overview of the studies on the FISSTbased multiple extended targets tracking techniques is analyzed here. The contents of the overview include the shape modeling methods, the optimal multitarget Bayes filter and its principled approximations, RFSbased trackvalued estimation and so on in the overview. Finally, on the basis of the existing research in these areas，some key issues of the RFSbased multiple extended targets tracking techniques are paying a great deal of attention to the researchers for solution. These contents consist of combination of shape modeling and group target profile modeling, multiple maneuvering extended target tracking, performance evaluation method of extended target tracking, extended target tracking based on nonlinear and nonGaussian, extended target tracking with nonstandard measurement.