All digital implementation of receiver is a main topic on digital communication recently. The design of interpolation filter is one of the important problems for all digital implementation of receiver. In this paper, for full response linear modulation signal, a interpolation criterion has been proposed. An interpolation formula is presented on bandwidth-limited transmission signal. For example, using the raised consine roll off function as the system pulse response, the feasiblity and effectiveness on the interpolation formula has been certified by theoretical and numerical analysis. The computer simulation result on 16-QAM signal is given.