This study select the diagnosis of postoperative colorectal cancer patients with stage II/III to adjuvant chemotherapy, and received 2 weeks and 3 weeks xelox adjuvant treatment process until disease progression or patients died or lost to follow-up. To analyze the difference in efficacy and safety of xelox in 2 weeks and 3 weeks of postoperative adjuvant therapy for colorectal cancer, so as to find a better postoperative adjuvant treatment model.

Inclusion Criteria:

• Carcinoma of the intestine confirmed histologically or cytologically
• Radical surgical resection was performed after diagnosis and the post operative stages were high-risk II or III patients
• The ECOG PS score less than or equal to 2 points
• No chemotherapy of any kind has been performed in the past
• Neutrophils acuity 1.5x10e9/L, platelets more than 100x10e9/L, college blood red protein more than 9g/dL
• liver function transaminase is less than or equal to 2.5 ULN, alkaline phosphatase is less than 2.5 ULN, and total bilirubin is less than 1.5 ULN

Exclusion Criteria:

• Patients with unresectable CRC
• Patients who have any form of chemotherapy before
• Participating in or having participated in clinical studies of other drug
• Patients have second primary malignant tumors of have other malignant tumors in the past five years
• There is evidence of allergic reaction to drugs in this study
• A history of ischemic heart disease in the past 1 year or patients with high risk factors for heart failure, or uncontrolled arrhythmias
• Severe active inflammation, including tuberculosis and HIV
• Long-term immunization or hormone therapy, except hormone replacement therapy at physiological dose
• Drug or alcohol addiction
• Get pregnant or breastfeed
• The investigator considers that the patient is not suitable for this clinical study due to any clinical or laboratory abnormalities or compliance problems