Abstract: The complete channel quality information is required to implement optimal bit and power loading algorithm, which is difficult to attain in practical system. To this end, this paper proposes a solving method based on resource block (RB) mutual information. A frequency domain link adaptative scheme is adopted to cope with the problems of combating frequency selective fading and insufficiency interleavingdepth of advanced channel coding (Turbo/LDPC). Firstly, modulation order is computed based on mutual information for each RB. And then, a uniform code rate is interpolated for multiple RBs. Both the analysis and simulation results show that the proposed method can obtain the spectrum efficiency very close to optimal bit and power loading algorithm.