[Purpose ] To investigate protein expression of the caudal -related homeobox gene 2 (CDX2) and its clinical significance in rectal cancer. [Methods] Western blot analysis was used to detect the protein expression of CDX2 in 50 tissue samples with rectal cancer and cancer adjacent tissues,as well as 20 samples with normal tissues from rectum as control group. [Results] The expression of CDX2 in rectal cancer tissues was lower than that of adjacent tissues,and the expression of CDX2 in cancer adjacent tissues was lower than that of the control group, both with significant differences (P<0.01).Expression of CDX2 in rectal cancer correlated with Dukes' stage,histologic differentiation,lymphatic node metastasis and 3-year survival,but had no obvious correlation with gender, age, site of lesion and pathologic type of the cancer patients. [Conclusion] Expression of CDX2 protein might be used to evaluate the malignancy, clinical stage, invasion, metastasis and prognosis of rectal cancer.