Purpose To investigate the influence of ametropia on stereopsis and its mechanism by using the disparity evoked potential testing. Methods A new set of static random dot stereograms was utilized as a stimulation to elicit the disparity evoked potentials in 21 ametropes and 40 stereo normal subjects. Rezults The P250 wave,which was related to stereoscopic stimulation in ametropes,was recorded in both the ametropes and emetropic stereo normal persons in this series,and the characteristic changes of P250 wave with increasing visual disparity in ametropes were similar to those in normal subjects.The differences of mean amplitudes and latencies of P250 waves between myopes and hyperopes were not significant. Conclusion Ametropia in full correction dose not significanly affect the function of stereopsis. (Chin J Ocul Fundus Dis,1998,14:225-227)