Successive interference cancellation (SIC) is an effective way of multipacket reception (MPR) to combat interference at the physical layer. The fact that the links decoded sequentially by SIC are correlated at the receiver poses key technical challenges. The study characterizes the link dependence and proposes simultaneity graph (SG) to capture the effect of SIC. Then, the interference number is defined to measure the interference of a link and facilitate the design of scheduling scheme. The study shows that link scheduling over SG is NP-hard, and the maximum interference number bounds the performance of maximal greedy schemes. An independent set based greedy scheme is explored to efficiently construct maximal feasible schedule. Moreover, with careful selection of link ordering, the study presents a scheduling scheme that achieves a better bound. Simulations evaluate the performance. The throughput gain is up to 110% over IEEE 802.11, while the complexity of SG is comparable with that of the conflict graph.