Analyzing the structure and character of several issues of the quasi-orthogonal space-time block code (QOSTBC), this paper proposes two novel quasi-orthogonal space-time block codes for four antennas. The novel codes are enriched the family of QOSTBC. Experiment results indicate that these two codes have good performance as TBH and Jafarkhani schemes, while the decoding complexity is the same as other quasi-orthogonal codes. By using zero-forcing decoding algorithm for novel codes, simulation results show that zero-forcing algorithm has better bit error rate performance as compared to the existing typical codes and can reduce the computation complexity at receiver.