Abstract: Objective: To observe the growth inhibitary effect of wild-type K-ras2 gene on colon adenocarcinoma cell line（Caco-2）. Methods: The colon adenocarcinoma cell line Caco-2 was transfected with the wild-type K-ras2 gene,and stable expression clones were selected.The growth of the colonadenocarcinoma cell was detected by monotetrazolium（MTT）,and the cell cycle analysis was carried out by flow cytometry（FCM）. Results: The expression of wild-type K-ras2 gene observably suppressed the growth of the colon adenocarcinoma cell line Caco-2 and arrested cell cycle in the G0/G1phase. Conclusion: The wild-type K-ras2 gene effectively suppressed the growth of colon adenocarcinoma cell line Caco-2.