Objective For better recognition of the hereditary nonpolyposis colorectal cancer (HNPCC) with reference to its clinical characteristics, diagnosis and treatment [WT5”HZ]Methods [WT5”BZ] A survey of 7 families of HNPCC patients was made [WT5”HZ] Results [WT5”BZ]Among the 7 families, 21 persons had colorectal cancer with age ranging from 26 to 79 years (average 46 years) The total of the colorectal cancer foci in 21 cases were 31,among which 16 were located proximal to,10 distal to the splenic flexure and 5 without definite record 61 5%(16/26) of the colorectal cancer foci were located proximal to the splenic flexure Six patients had multifocal colorectal cancer, which accounted for 28 6%(6/21) of all cases [WT5”HZ] Conclusions [WT5”BZ] HNPCC patients and their family members should be followed up regularly for early diagnosis and treatment of the disease and for better prognosis