Objective To investigate the significance and expression of E-cadherin(E-CD),focal adhesion kinase(FAK)and FAK py397 in rectal cancer.Methods Thirty paraffin specimens of rectal cancer and adjacent tissues collected from 2001 to 2002 and 35 fresh specimens of rectal cancer and adjacent tissues resected from 2006 to 2007 at People's Hospital of Wuhan University were adopted in this study.The expression of E-CD,FAK and FAK py397 was detected by immunohistochemistry and Western blot.All data were analyzed using chi-square test.Results E-CD was positively expressed in the membranes of epithelial cells in normal rectal mucosa,while no E-CD expression was found in the membranes of epithelial cells in rectal cancer tissues.There was a significant correlation between the expression of E-CD,FAK,FAK py397 and tumor difierentiation,depth of invasion and lymph node metastasis(χ~2=7.099,18.358,25.612;12.316,28.823,23.168;8.927,18.122,22.620,P＜0.05),while no relationship between the expression of E-CD,FAK,FAK py397 and age,sex was detected(χ~2=0.439,1.899,3.676;0.541,4.051,1.135,P＞0.05).The expression levels of FAK and FAK py397 were 83% (54/65)and 68% (44/65)in rectal cancer tissues,and were 31%(20/65)and 26% (17/65)in adjacent tissues,with significant difference(χ~2=33.707,34.163,20.897,P＜0.05).Conclusion Lost expression of E.CD in the membrane of rectal cancer tissue and elevated expression of FAK and FAK py397 in the rectal cancer tissue might be related to the invasion and metastasis of rectal cancer,which may predict the biological behavior of rectal cancer.