Ojective To study the expression and clinical significance of β -catenin in colorectal carcinoma . Methods The β -catenin expression was examined im munohistoche mically in 60 cases of colorectal cancer,20 cases of colorectal adenoma and 20 cases of normal colorectal tissues. Results The membranous expression of β-catenin in cancerpatients (65 % )was significally lower than that of colorectal adenomas (90 % )and normal colorectal tissues (100 % ) .The nuclear expression of β-catenin was found in 5 9% of colorectal cancer and 30 % of colorectal adenoma and 0 % of normal colorectal tissues (P 0 .0 5 ) ,but not related to location , depth of invasion and Duke’s stage .Reduced membranous expression was correlated to short survival. Conclusion The abnormal expression of β -catenin is associated with the carcinogenesis of colorectal cancer.Ex- pression of β -catenin may be biological marker of invasion and metastasis of colorectal cancer.