Abstract: Objective To investigate the association between galectin-3 expression and biological behaviors of human colorectal carcinoma.Methods SP immunohistochemistry was used to detect the expression of galectin-3 in 158 cases of paraffin-embedded specimens(including 30 normal mucosa,25 adenoma,65 carcinoma and 38 metastatic tumor speciemns).Real-time RT-PCR was performed to detect galectin-3 mRNA expression in 31 pairs of fresh carcinoma and corresponding adjacent normal mucosa specimens.Results The expression levels of galectin-3 was significantly different between normal mucosa and adenoma tissues(P<0.001),and moderately or well differentiated colorectal carcinomas showed significantly lower expression of the galectin-3 than the poorly differentiated carcinomas(P=0.03).Invasive carcinomas exhibited higher galectin-3 expression levels than non-invasive ones(P<0.001),and galectin-3 expression in the colorectal carcinomas was significantly related with the lymph node metastasis(P<0.001).Galectin-3 mRNA expression in poorly differentiated colorectal carcinomas was about 1.98 times that in moderately or well differentiated colorectal carcinomas(P=0.03),and in invasive carcinomas,galectin-3 mRNA expression was 1.67 times higher than that in non-invasive ones(P<0.001).Galectin-3 mRNA expression in tumors with lymph node metastasis was 1.91 times that in non-metastatic tumors(P=0.013).Conclusion Galectin-3 expression is positively correlated with and invasion,poor differentiation and metastasis of colorectal carcinoma.