Inclusion Criteria:  i. Age : 20 years old or more and lesser than 75 years old ii. Agreement of this study iii. Clinical stage II or III colon cancer with colonic obstruction which is confirmed by pathologic review and imaging study.  iv. Colon cancer located beween distal T colon and Rectosigmoid junction colon which is defined as a tumor above 15cm from anal verge.  v. Colonocopic fiding: tumor involving whole circumference of the lumen, impossible to pass endoscope through the tumor vi. SEMS placement vii. no colonic injury and successful decompression of the colon with in 48 hours after SEMS placement.  viii. ECOG performance 0-2 ix. ASA ≤ 3 x. Appropriate function of the vital organ (acceptable liver enzyme and BUN/Cr) xi. Appropriate function of hematopoietic system (platelet ≥100,000ul, neutrophil ≥2,000ul) xii. If the patient is female in fertile period, urine hCG test is negative and she has no plan of pregnancy with 6 months after the termiation of whole treatment.  xiii. If the patient is male in fertile period, he agrees with contraception during treatment period and 6 months after the termination of whole treatment.  Exclusion Criteria:  i. any suspicious distant metastasis ii. any other primary malignant lesion iii. Clinical stage T1or T2 and N0 iv. the sign of perforation or severe ischemia requiring ememgency operation v. the complication related to SEMS placement (severe bleeding and perforation after SEMS placement) vi. ASA 4 or more vii. ECOG 3 or more viii. colonic obstruction by benign stricture ix. pregnant woman or woman who is breastfeeding x. the paitents who already enrolled into other study or are taking medicine related to any clinical trial xi. the patients who are taking sorivudine xii. the patients who are taking Tegafur/gimeracil/oteracil xiii. the patietns who have a medical history of hypersensitivity reaction to 5-FU, oxaliplatin, leucovorin,or any medication including platinum.  xiv. Inappropriate function of vital organ (impaired renal function, elevated liver enzyme, and so on ) xv. Inappropriate function of hematopoietic system (platelet <100,000ul, neutrophil < 2,000ul) xvi. Genetic problem such as galactose intolerance, Lapp lactase deficiency, or glucose-galatose malabsorption)