Objective To investigate the effects of laporoscopic resection applied to colorectal cancer patients on metabolism. Methods According to patients' choice of operation, either laparoscopic-assisted (n = 22, experimental group) or open(n = 27, control group) resection of colorectal cancer was performed. The levels of electrolyte were assayed preoperatively, postoperatively and on the time of 24 hours after opera-tion. Rseults There was no significant difference in the level of electrolyte before operation between the two groups (P > 0. 05). Compared with the preoperative period, the level of serum potassium in the both groups were significantly increased after operation(P < 0. 05), and 24 hours later, the levels of electrolyte was not significantly different in both the two groups (P > 0. 05). During the postoperative period, the level of serum potassium in the experimental group was lower than the control group(P <0. 05), while the level of HCO_3~- was higher than the control group(P <0. 05), and there were no significant differences in the level of serum sodium, chloride and calcium between the two groups(P > 0. 05). Conclusions Laparoscopic-assisted re-section of colorectal cancer gives lower levels of stress responses compared to open surgery. However, it shows higher effect on the level of HCO_3~- , and must be paid more attention during operative and postopera-tive period.