【Abstract】ObjectiveTo detect the expression of human papilloma virus(HPV) 16 E7 was detected in colorectal adenocarcinoma tissue and normal mucosa. MethodsEighty-two patients with primary colorectal adenocarcinoma were selected in this study. The samples were taken from the tumor and the adjacent normal mucosa (10 cm away from the tumor) in each patient. Polymerase chain reaction (PCR) and immunohistochemistry were used to detect HPV16 E7 DNA and protein respectively. ResultsHPV16 E7 DNA expression was significantly higher in colorectal carcinoma (51.22%,42/82) than that in adjacent normal mucosa (4.88%,4/82), P＜0.01. A correlation was found between HPV16 E7 DNA expression and tumor location (P＜0.05)，18.18% in the ascending colon carcinoma and 64.10% in the rectal carcinoma. HPV16 E7 DNA expression was also associated with Dukes stage（P＜0.01）, but was not correlated with cancer differentiation. HPV16 E7 protein expression was mainly dectected in the nuclei of tumor cells with immunohistochemistry. There was a correlation between the expression of HPV16 E7 protein and HPV16 E7 gene. PCR had a higher sensitivity than immunohistochemistry. ConclusionHPV16 infection rate is much higher in the colorectal carcinoma than that in the adjacent normal mucosa, which indicates that HPV16 infection exists in some colorectal carcinomas. The high infection rate of HPV16 E7 is associated with advanced Dukes stage and proximity to anus.