Inclusion Criteria:

- Informed consent

- Pathologically confirmed adenocarcinoma

- Pre-surgery image staging as (CT/MRI):T2-3,N0-2,M0,(TNM stage，AJCC，version of 2003)

- Single tumor locating at cecum, ascending colon, descending colon, sigmoid colon,
rectosigmoid junction, rectum(distance from anal verge more than 7cm)

- Tumor diameter less than 6cm

- Age 18-75 year

- ECOG 0-2

- Predicted survival longer than 6 months

- Normal liver, renal, bone marrow function: (GPT less than 2 ULN，total bilirubin less
than 1.5mg/dl，Cr less than 1.5 ULN，WBC more than 4×109/L，PLT more than 100×109/L)

- No previous history of gastrointestinal surgery

- No previous history of chemotherapy or radiotherapy

Exclusion criteria

- Severe and uncontrolled medical disease including unstable angina pectoris, cardiac
infarction and cerebral attack in 6 months

- Could not tolerant general anesthesia or surgery for other organ dis-function

- Allergy to chemotherapeutical agents in the protocol

- History of other malignant tumor within 5 years

- Severe mental disorder

- Continued systematic steroid therapy

- Woman during pregnancy or lactation

- Under study of other clinical trial

- No compliance of the protocol

- Discovery of distant metastasis during surgery

- Postsurgery stage of I or IV tumors