Correlation functions of a conformal field theory (CFT) can be constructed from two- and three-point functions. However, the planar four-point functions of a large Nc CFT cannot be recovered by the planar two- and three-points. We apply the superconformal block decomposition to the four-point functions of N=4 SYM, and extracted the non-planar information of multi-trace operators. In addition, we identified non-scalar superconformal primary fields which contribute to the OPE limit. This work is based on collaboration with Yusuke Kimura (OIQP).