Abstract： Objective To retrospectively analyze medical data of patients with colorectal cancer (CRC) so as to provide evidence for clinical use of opportunistic screening.Methods A total of 2450 CRC patients (male 1377,female 1073) who were treated at five hospitals in North China during October 2001 and September 2011 and had complete medical records and pathological results were recruited.The correlations of incidence of CRC with age,gender,tumor location and histological types were analyzed.Results Of all the CRC patients,those less than 50 years old accounted for 18.14％ ; and the incidence of CRC was substantially increased in those over 50 years old.Seventy-three percent of tumor occurred at the rectum and sigmoid colon,6％ at descending colon,7％ at transverse colon and 14％ at ascending colon.Moderately,well or poorly differentiated adenocarcinoma accounted for 50.33％,40.35％and 9.32％,respectively.Histological differentiation was not correlated with age and gender ( P ＞ 0.05 ).Conclusions Age and gender should not be considered a determination of opportunistic screening for CRC.Colonoscopy is recommended as an alternative CRC screening procedure.