This paper reports the photoresponse of YBaCuO thin film at liquid nitrogen (LN) temperature range under the irradiation of He-Ne laser.at or near the middle point of the film's transition temperature, the obtained voltage response signal of photolithographic YBaCuO film to 1.5mW He-Ne lasr chopped at a frequency of 0.1Hz is 10V/W. the relation of the response signal to chopping frequency and the influence to the results by choosing the working temerature are discussed in detail.