Single incision laparoscopic surgery (SILS) is the further development of the concept of minimally invasive surgery for colorectal cancer,which rapidly developed in the field of colorectal surgery. Through the development of single hole laparoscopic colorectal cancer radical surgery and clinical study and follow up accordingly, evaluating the feasibility, surgical effectiveness and economy help to promote the popularization and application of single hole laparoscopic techniques in the field.

The patients with colorectal cancer will randomly divided into single incision laparoscopic surgery group and conditional laparoscopic surgery group. The operation time, blood loss, the incidence of lymph node , the number of postoperative complications, the gastrointestinal function recovery time, postoperative hospital stay，the number of local recurrence and distant metastasis, survival rate and the total cost of hospitalization will be evaluated to confirm the feasibility of single incision laparoscopic surgery is effective and economical. It is worthy of clinical application.

Inclusion Criteria:

• 18 years < age < 80 years
• Tumor located in colon and high rectum ( the lower border of the tumor is above the peritoneal reflection)
• Pathological colorectal carcinoma
• Clinically diagnosed cT1-4aN0-2 M0 lesions according to the 7th Edition of AJCC Cancer Staging Manual
• Tumor size of 5 cm or less
• ECOG score is 0-1
• ASA score is Ⅰ-Ⅲ
• Informed consent

Exclusion Criteria:

• Body mass index (BMI) >30 kg/m2
• The lower border of the tumor is located distal to the peritoneal reflection
• Pregnant woman or lactating woman
• Severe mental disease
• Previous abdominal surgery（except appendectomy and cholecystotomy）
• Emergency operation due to complication (bleeding, perforation or obstruction) caused by colorectal cancer
• Requirement of simultaneous surgery for other disease