This paper proposes a micro-system design for the wireless endoscopic capsule, which assures that the capsule has small size(less than 25 mm*10 mm), can implement the diagnosis of whole human digestive tract and provide real time endoscopic image monitoring. The designs of two core hardware parts inside the capsule, low power analog-digital mix-mode single-chip and micro-antenna are discussed in detail. A new automatic retransmission request (ARQ) communication scheme is proposed for the high quality image communication system. The micro-antenna design with less than 9 mm diameter is implemented. The digital circuits have been verified on FPGAs and analog circuits have been simulated. The analog-digital mix-mode single-chip has been implemented in 0.18 mum CMOS process