Abstract: To investigate the expression of leptin receptor (Ob- R) in colorectal adenocarcinoma tissue and to explore the effect of tumor angiogenesis and possible mechanism. Methods:Thirtyfive patients with colorectal adenocarcinoma, confirmed pathologically, were included in this study. Immumohistochemical staining was performed to detect the expression of the Ob- R, CD105, nuclear factor- kappa B (p65) （NF- κB (p65)）in tumor tissues and their own normal controls. Image analysis software was used for semi- quantitative assessment. Results: The integrated optical density of the Ob- R and NF- κB (p65) and the microvessel density (MVD) marked by the CD105 in colorectal adenocarcinoma tissue were higher than in normal controls. The positive expression of Ob- R on vascular endothelial cells was seen in 63.6% of the cases of cancer group and the MVD in cases of the group was higher compared to the negative group (38.21±2.78 vs 27.50±2.95, t=2.602, P<0.05); the positive expression of NF- κB (p65) on the nucleus of vascular endothelial cells was seen in 68.6% of the cases of cancer group, and the MVD in the cases of the group was higher than the negative group (37.53 ±3.07 vs 28.42±2.63, t=2.146, P<0.05). The expression of the Ob- R and NF- κB (p65) on similar location was observed and, the semi - quantitative assessment showed that there was a significant association between the two (r=0.705, P<0.05). Conclusion: The study suggests that increased expression of Ob- R contributes to tumor angiogenesis in colorectal adenocarcinoma, probably through activation of the NF-κB pathways.