To search for a new better method of making paraffin section in the rat retina,and to explore the relationship between the expression of apoptosis protein Bax and the time of death in retinal cells. METHODS:According to different time of the death, Wistar rats were randomly divided into 4 groups(group A,0 hour; group B,12 hours; group C, 24 hours; group D, 36 hours).After using the new fixative method for rats retina, each group was respectively observed and analyzed by the HE, immunohistochemistry and immunofluorescence; then processed by image analysis and statistical treatment. RESULTS:Each group of retinal tissue was essentially integrated, the cells form distinct; Each retinal layer became raritas and exhibited pyknosis gradually as time prolonging; the results of variance of immunohistochemistry and immunofluorescence indicated that the expression of Bax in groupA, groupB, groupC rat retinal cells tended to increase with time, but group D reduced; there was a significant difference between any two groups by analysis of variance(P<0.05). CONCLUSION:The new improved method of making paraffin section is better comparatively, possesses of popularization and application value. The expression of apoptosis protein Bax in retinal cells has correlation with postmortem interval(PMI), which provides scientific base for the clinical application of it.