In this paper, a novel design of amplitude phase shift keying-aided space-time block coded differential spatial modu-lation (APSK-STBC-DSM) is proposed. This design conceived not only maintains the diversity benefits of the space-time block coded differential spatial modulation (STBC-DSM) system, but also conveys extra information bits with the aid of amplitude phase shift keying (APSK), so as to enhance the transmission rate. Moreover, an improved low-complexity detector is also proposed, in order to achieve near-optimal detection performance. Ultimately, simulation results exhibit that the proposed APSK-STBC-DSM system is capable of providing significant bit error rate (BER) performance gains over conventional STBC-DSM and other differential spatial modulation (DSM) counterparts.