We present an innovative concentration generator with on chip vacuum pump. The concentration generator is contained the microfluidic channel and self-priming microfluidic device. The microfluidic channel structure is made up from polypropylene which characteristic are ultra-thin (under than 100 um), cost effective, mass producible, rapid fabrication process. The self-priming microfluidic device also has many feature, like thin residual layer (under than 100 um), on chip new pumping method, standing alone device, minimal manual operation, commercialize. In this paper, we propose the design of microchannel which generating concentration gradient, and introduce the fabrication process, simulation, and experimental result. Due to all the advantages, we think this concentration generator system can be used on biochip.