Modulation transfer function is a powerful tool to evaluate the imaging performance of optics system.In order to expediently evaluate imaging quality of imaging sensor,a new method using sine mask to measure modulation transfer function is presented,which is based on the interferential fringe measurement method.The sine pattern generated by sine mask is directly projected on the imaging sensor,and the sine image is achieved.Then the modulation transfer function can be calculated.The approximate experiment is carried out,making use of rectangular grating which spatial frequency is 25 l/mm.The approximate modulation transfer coefficient is obtained with the corresponding data processing technology.The result indicates that such method is agreeable.