Objective：To explore the proliferation effect of long noncoding RNA（LncRNA）AGAP2-AS1 on colorectal cancer（CRC）cell lines and the associated signaling pathways. Methods：We conducted qRT-PCR to investigate mRNA levels of AGAP2-AS1 in 50 paired CRC tissues and the corresponding normal mucosa tissues. SiRNA targeting AGAP2-AS1 was transfected into DLD-1 and HT29 cell lines，qRT-PCR was performed to detect the transfection efficacy of siRNA and AGAP2-AS1 downregulated DLD-1 and HT29 cells were used for further investigating the role of AGAP2-AS1 in CRC cell proliferation through CCK8-kit and colony formation assay. Cell cycle distributions were analyzed by a flow cytometer. Western blot was conducted to explore the protein levels of MAPK signaling pathway，including Ras，Raf-1，MEK and ERK. Results：The mRNA levels of AGAP2-AS1 were markedly upregulated in CRC tissues rather than the corresponding normal tissues. Loss of AGAP2-AS1 greatly suppressed cell proliferation of DLD-1 and HT29 cells，increased percentage of G0/G1 phases population and downregulated the protein levels of Ras，p-Raf-1，p-MEK and p-ERK. Conclusion：LncRNA AGAP2-AS1 could promote colorectal cancer cell proliferation through Ras/MAPK signaling pathway.