Abstract: Objective To observe the effect of thrombopoietin（TPO） on MO7e cells and the relation between its dose,use of time and dynamics of platelets. Methods MO7e cells were calculated by MTT for the TPO concentration-MO7e cell growth curve.The number and morphology of MO7e cells were observed under an inverted microscope. Results TPO could stimulate the growth of MO7e cells.The number of MO7e cells reached its peak when TPO was used at the concentration of 256ng/ml or 48h after TPO was used. Conclusion TPO can stimulate the growth of MO7e cells when it is used at the concentration of 256ng/ml and at the time of 48h.