Colorectal cancer (CRC) is one of the most frequent cancer in numerous of countries worldwidely. The initiation and progression of CRC is an extremely complex process, and have been suggested a correlation with Long non-coding RNAs (lncRNAs). Our results showed that lncRNA-422(ENST00000415820) significantly downregulated in the tissues and serum of CRC patients, and is closely associated with the poor prognosis. Then gain or loss of lncRNA-422 models in SW480 and SW620cells were established. The results showed that lncRNA-422 overexpression inhibited cell proliferation, migration, and invasion. Knockdown of lncRNA-422 promoted tumorigensis. Western blot and qRT-PCR were performed to examine the activity of the PI3K/AKT/mTOR pathway in CRC cells after alternation of lncRNA-422. Results showed that lncRNA-422 acts as a tumor suppressor by PI3K/AKT/mTOR pathway in CRC (C) 2017 Published by Elsevier Inc.