Inclusion Criteria:

1. Pathologically proved colorectal cancer (either adenocarcinoma, mucinous carcinoma, or signet-ring cell carcinoma).
2. Tumor is mainly located in between cecum and upper rectum, excluding that invades to lower rectum.
3. Stage III cancer by General Rules for Clinical and Pathological Studies on Cancer of the Colon, Rectum and Anus (6th ed.), excluding si(ai), n(-), M(-).
4. No synchronous colorectal cancer which invade muscularis propria or deeper.
5. Tumor resection with D2 or D3 lymph node dissection was performed.
6. Pathological determination of curability of tumor resection is cur A.
7. Age at registration is above 20 and below 75 years old.
8. ECOG Performance status is 0 or 1.
9. No prior chemotherapy or radiation therapy.
10. Intake of normal diet and oral drugs is possible.
11. Major organ function is preserved. WBC>=3,000/mcl, PLT>=100,000/mcl, GOT<=100 IU/L, GPT<=100 IU/L, T.Bil <=2.0 mg/dl, Cr<=1.5 mg/dl
12. Adjuvant chemotherapy can be started within 9 weeks after surgery.
13. Written informed consent is taken.

Exclusion Criteria:

1. Active co-existing malignancy （synchronous or metachronous malignancy whose disease free period is within 5 years). Carcinoma in situ is eligible.
2. Severe postoperative complications which do not resolve until registration.
3. There is following complication. insulin-controlling or uncontrollable diabetes mellitus, uncontrollable hypertension, myocardial infarction within six month or unstable angina pectoris, liver cirrhosis, interstitial pneumonia, pulmonary fibrosis, severe emphysema
4. Pregnant or breast-feeding woman.
5. Difficult to participate with the trial, having mental disorder or psychiatric symptoms.
6. Judged to be inappropriate to register.