A novel microfluidic chip is developed for crossflow filtration plasma from the whole blood which is carried out in a continuous manner. This microfluidic chip was made of a silicon substrate sealed with a compound cover. The silicon substrate fabricated by micro-electro-mechanical system (MEMS) technology consisted of microposts array, microchannels and reservoirs. Then the silicon substrate was characterized by Scaning Electron Microscopy (SEM). The performance of the microfluidic chip was valued by the experiments of plasma isolation. During more than one hour of continuous blood infusion through the chip, there were no problems of jamming or clogging, and the plasma selectivity of 97.78% was achieved. Due to the chip’s simple structure and control mechanism with a continuous, real time operating manner, this microfluidic chip is easily expected to be integrated into micro total analytical system (μTAS) which will create a microanalysis system for point-of-care diagnostics. The microfluidic chip was made of a silicon substrate sealed with a compound cover. The silicon substrate fabricated by micro-electro-mechanical system ( Then the silicon substrate was characterized by Scaning Electron Microscopy (SEM). The performance of the microfluidic chip was valued by the experiments of plasma isolation. During more than one hour of continuous blood infusion Through the chip, there were no problems of jamming or clogging, and the plasma selectivity of 97.78 was was. Due to the chip's simple structure and control mechanism with a continuous, real time operating manner, this microfluidic chip is easily expected to be integrated into micro total analytical system (μTAS) which will create a microanalysis system for point-of-care diagnostics.