Visual comfort is an important index of performance evaluation about autostereoscopic displays.Parallax and spatial frequency in stereo images are assumed to exert substantial influence upon perceiving depth of human eyes,thus having significant effect on visual comfort.In this paper,3D modeling software 3D MAX and image processing software photoshop are used to get stereo images which contain different parallax and spatial frequency.Both objective evaluation and subjective evaluation are adopted to assess comfort degree of the viewers,the relationship between parallax as well as spatial frequency and visual comfort is confirmed.In the case of comfortable viewing,parallax range and the corresponding spatial frequency scope are obtained.According to the experimental results,blur caused by low spatial frequency can improve visual comfort in stereo images.