Abstract: Laser spot center location is a key technique in the field of optical measurement. Based on the analysis of algorithms commonly used, a Gaussian fitting based laser spot center location method was presented. The unsaturated part of laser spot image was used to fit the Gaussian surface, based on which the amplitude of the fitting function could be looked upon as the laser spot center. In order to verify this algorithm, an artificial light spot was used firstly, experimental results showed that the error of this algorithm was much less than 0.1 pixels; and then a measuring system which mainly consisted of high precision motorized translation stage of one dimension, CCD camera and laser was constructed, the acquisition and analysis of laser spot image were accomplished by computer automatically, experimental results showed that the root mean square error between the algorithm and theoretical analysis was only 0.1 pixels, which had high accuracy.