The purpose of this study is to verify the 5-year disease free survival (DFS) of resectable colorectal cancer after laparoscopic surgery according to a Chinese Operative Standard was not inferior to open surgery.

Study type：Interventional Study phase：Phase III Objectives of Study：to verify the 5-year DFS of resectable colorectal cancer after laparoscopic surgery according to a Chinese Operative Standard was not inferior to open surgery.

Study design：Randomized parallel control

Inclusion Criteria:

1. informed consent
2. single colorectal adenocarcinoma, located at any segment of the colorectum with lower margin 5cm or more to the dental line
3. cTNM：colon cancer T1-4N1-2M0，rectal cancer T1-3N1-2M0，longest diameter no more than 6cm
4. age less than 80 years old
5. normal blood routine test and hepatic or renal function test
6. no gastrointestinal surgery history or chemotherapy, radiation, No complete obstruction.

Exclusion Criteria:

1. severe comorbidity such as heart attack or stroke, malignance in 5 years
2. can not tolerate to general anesthesia, pneumoperitoneum or surgery
3. pregnant or during breast-feeding period
4. attending other clinical trial involving therapy
5. cannot or disagree to attending the clinical trial