Abstract: Objective To investigate the relationship and clinical significance of Bag-1 expression in colorectal carcinoma tissues and normal colorectal tissues,and its relationship with lymphnode metastasis. Methods The expressions of Bag-1 in 55 patients' colorectal carcinoma tissues (case group) and 25 normal colorectal tissues (control group) were examined by Western blot analysis and RT-PCR. Results (1) The expressions of Bag-1 in 55 colorectal carcinoma tissues were inordinately detected,the protein relative strength of Bag-1 was (5~109,64.09±31.59).We found that the protein relative strength of Bag-1 in colorectal carcinoma tissues with lymphnode metastasis (30.34~109,81.05±19.64) was higher than that in colorectal carcinoma tissues without lymphnode metastasis (5~70.13,26.19±16.32) (P<0.001),however,both of them were obviously higher than that in normal colorectal tissues (0~10,4.28±2.82)(P<0.001).(2) The gene fragments of Bag-1 and β-actin primers amplified were clearly visible by electrophoresis and EB staining.The length of the gene fragments amplified was 331 bp and 254 bp respectively,which was consistent with that we designed.The relative expression value of Bag-1 mRNA in 55 colorectal carcinoma tissues was (0.33~1.21,0.74±0.26).The relative expression value of Bag-1 mRNA in colorectal carcinomas tissues with lymphnode metastasis (0.52~1.21,0.87±0.21) was higher than that in colorectal carcinoma tissues without lymphnode metastasis (0.33~0.65,0.45±0.09)(P<0.001),however,both of them were significantly higher than that in normal colorectal tissues(0~0.22,0.10±0.06）(P<0.001). Conclusion The overexpression of Bag-1 plays an important role in the development and progression of colorectal carcinomas.The expression level of Bag-1 is correlated with lymphnode metastasis.Bag-1 can serve as a biomarker to prognosticate the metastasis potentiality of colorectal carcinomas.Detecting Bag-1 may contribute to estimate the prognosis of patients.