Abstract　 　　
　Galaxy-galaxy lensing though statistical in nature, has its own unique power to proble the connection between the dark matter halos and galaxies formed inside. A lot has been done to study the mass, the shape of the dark matter halos and the alignment between the major axis of the central galaxies and halo major axis. For galaxy groups containing two distinct species of galaxies know as central and satellite, which are considered to be the tracers of host halo and subhalo respectively are the sample we have at hand to proceed the lensing study. The detected lensing profile of centrals and satellite are different. By comparing the theory and observation, we can constrain the process of galaxy formation. In this talk, we generalise the applications of galaxy-galaxy lensing and an accurate image processing method tested by three independent simulations. Then, we show the recent lensing signal around 201  X ray and optical cross-identified groups.