Abstract: Objective To investigate the expression and clinical significance of EGFR and Ras protein in the carcinogenesis of colorectal carcinoma. Methods By immunohistochemical SP method,EGFR and Ras protein expressions in 115 cases of colorectal cancer,36 cases of colorectal adenoma,43 cases of normal colorectal mucosa were detected.The relationship of between the clinical and pathological featwres was analysized. ResultsIn carcinoma group，adenoma group and adjacent normal mucosa group，the positive expression rates of EGFR were 62.61%(72/115），30.56%(11/36）and 12.77%(6/47) respectively，with statistic difference(P<0.05).The positive rates of Ras expressions were 46.09%(53/115)，38.89%(14/36) and 10.63%(5/47) respectively.The positive rates of the two former groups were obviously lower than those of the last group (P<0.05）.In carcinoma patients that infiltrated to submucosa and muscular layers，subserous layer or penetrated subserous layer，the positive expression rates of EGFR were 36.84%(7/19)，65.82%(52/79) and 70.59%(12/17) respectively,the latter two was higher than the former(P<0.05).The positive rate of Ras protein expression in well- moderate differentiation was higher than that in poor differentiation 59.52%(25/42) vs.38.36%(28/73)(P<0.05). Conclusion The expression of EGFR protein had positive correlation to the depth of invasion.The expression of Ras protein had negative correlation to the cell differentiation.A test combined EGFR and RAS will help to improve evaluation in the diagnosis and prognosis of colorectal carcinoma.