Objective: To compare the impacts between laparoscopic and open surgery on immune function in treatment of colorectal cancer. Methods: Literature of randomized controlled trials (RCT), published between January 1995 and December 2012 in both Chinese and English, comparing the influences between laparoscopic and open surgery on immune function in treatment of colorectal cancer were collected, and the related parameters were evaluated using Meta-analysis. Results: Thirteen studies involving 959 patients were finally selected, with 465 cases in laparoscopic surgery group and 494 cases in open surgery group. Results of Meta-analysis showed that the activities of CD3+ and CD4+ T lymphocytes, and CD4+/CD8+ ratio in laparoscopic surgery group were significantly higher than those in open surgery group on postoperative day (POD) 1 to 7 (all P<0.05); the activity of natural killer cells in laparoscopic surgery group was significantly higher than that in open surgery group (time points for comparison were POD 1, 3 and 7) (P<0.05); the immune globulin levels (IgA, IgG and IgM) between the two groups on POD 3 showed no significant difference (all P>0.05); the interleukin 6 level in laparoscopic surgery group was significantly lower than that in open surgery group on POD 1 (time points for comparison were 4 h after operation, and POD 1, 3 and 7); the C-reactive protein levels in laparoscopic surgery group were significantly lower than those in open surgery group on POD 1 to 7 (time points for comparison were POD 1, 3, 7 and 14) (all P<0.05). Conclusion: Laparoscopic colorectal cancer surgery exerts a less negative influence on the immune system compared with open surgery, and has a better preservation of the immune function that is conducive to preventing pathogenic invasion and killing cancer cells.