Objective：To discuss the value of congenital hypertrophy retinal pigment epithelium （CHRPE） in diagnosis of familial adenomatous polyposis （FAP）. Methods： Twenty two FAP patients who have received treatment in our department （January 2001 to June 2003） and 10 patients with sporadic colorectal polys （as control group） were subjected to optical fundus examination. The incidence, morphological feature and distribution of CHRPE were analyzed. Results： Seventeen（81.8%） of the 22 FAP patients were found to have CHRPE in optical fundus. The lesions showed a bilateral and multiple（≥2） distribution along the peripheral vessels with oval pigmentation. One patient was found to have CHRPE in the control group. Conclusion： Optical fundus examination is a highly sensitive and specific adjuvant diagnosis for FAP. It is a safe and effective way for screening FAP in FAP family members