Abstract: This paper presents a modularized, internal local bused, real-time MPEG2 system layer de-multiplex in DVD. The circuit general architecture, start code detection circuit, PES header decoding circuit and PLL circuit are discussed in detail. The FPGA implementation results of this real-time de-multiplex are introduced. It is a simple, resource saved, easy to be integrated system with functions of multi-PES distribution, system clock recovery and etc. It is proper for the applications in DVD and some other relative fields.