A new micro cell chip which can induce stem cells to differentiate into specific body cell types has been designed and fabricated for tissue engineering. This paper presents the test results of a micro cell stimulator which can provide a new miniaturized tool in cell stimulation, culture and analysis for stem cell research. The micro cell stimulator is designed to apply compressive pressure to the hMSCs (human mesenchymal stem cells) for inducing osteogenesis. The micro cell stimulator is based on the pneumatic actuator with a flexible diaphragm which consists of an air chamber and cell chambers. The hMSCs under cyclic compressive stimulation for one week were observed and assessed by monitoring CD90 (Thy-1), actin, alkaline phosphatase (ALP) and alizarin red expression. The results suggest that cyclic mechanical stimulation is attributed to the different phenomenon of cultured hMSCs in cell proliferation and differentiation. These results are important for the feasibility of the micro cell stimulator to provide the reduction of the necessary quantity of cells, process cost and the increase of the throughput.