A real-time audio processing system based on digital signal processor (DSP) is designed. With the interface characteristics of TMS320DM642 and audio CODEC chip TLV320AIC23B, the connection meth. ods of multi-channel audio serial port (McASP) and four pieces of TLV320AIC23B are introduced in detail. And the software implementation methods are given to sample quadruple audio signals simultaneously. The signals are processed by filtering algorithm and processed waveforms are displayed on computers by CCS3.3 at real time. A whole audio signal processing system is completed so that stimulated audio signals can be sampled, fil. tered and replayed.