 Irinotecan and capecitabine are approved to be the effective drugs for the advanced colorectal cancer patients. However, the combination of these two drugs are not regularly recommended due to the severe diarrhea as the most common adverse event.This study was designed to explore whether the single-week regimen of irinotecan plus capecitabine improves efficacy and does not increase the toxicity in advanced colorectal cancer patients in China. 