Objective To study the relationship between gastrin and c-myc, c-fos expression in colorectal cancerous tissue and the mechanism of gastrin effect on colorectal cancer.Methods The gastrin and c-myc, c-fos expression in 48 cases of colorectal cancerous tissue and cancer-adjacent mucosa were detected with immunohistochemistry techniques. Results　The positive rate of gastrin in colorectal cancerous tissue was 39.58%. The rate of the well differentiated adenocarcinoma was higher than that of the poorly differentiated and mucinous adenocarcinoma(P＜0.05). The positive rates of c-myc and c-fos in colorectal cancerous tissue were higher than those in cancer-adjacent and normal mucosa. The positive rate of c-myc and c-fos in the group with gastrin positive expression were 78.94% and 73.68%, higher than those in the group with negative gastrin expression(37.93% and 31.04%). Conclusion Some of colorectal cancer cells formed and secreted gastrin through autocrine. The increase of c-myc, c-fos etc oncogene expression probably stimulate the cancer cells proliferation.