I will talk on the result of 3.64 squre degree weak lensing survey for Coma cluster z=0.0236 by Subaru Prime Forcus Camera to directly measure subhalos masses and their mass function. We convincingly detected 32 subhalos down to the order of 10^-3 of the virial mass of the cluster. The observed mass fuction spanning to two orders of magnitude in mass is is consistent with the prediction of CDM paradigm.