Objective To investigate the association between RNA methylation recognition protein， YTH N6- methyladenosine RNA binding protein 2（ YTHDF2）， and the chemotherapy resistance in O6- methylguanine-DNA- methyltransferase（ MGMT） methylated glioma， and to reveal the underlying mechanism.Methods A total of 325 patients from Chinese Glioma Genome Atlas（ CGGA） were included in this study. General and clinical information（ including histopathological and molecular pathological information， overall survival， postoperative adjuvant therapy information and gene expression profile information including YTHDF2） were collected. The Kaplan-Meie curves and Log-rank testing were used to study the relationship among YTHDF2 expression level， the sensitivity of temozolomide（ TMZ） treatment and the prognosis of glioma. A glioma cell model was established with stable YTHDF2 knockout by lentivirus infection. The cytoviability of glioma cells with different expression levels of YTHDF2 was detected by cell cytoviability kit 8（ CCK-8） after TMZ treatment. Gene Set Enrichment Analysis（ GSEA） and gene ontology（ GO） functional annotation were used to study the potential mechanism underlying the role of YTHDF2 in the resistance of glioblastoma to TMZ. Results Clinical database cohort analysis showed that the overall survival of gliomas patients with high expression level of m6A recognition protein YTHDF2 after chemotherapy was significantly shorter than those with low expression level of YTHDF2（ P ＜ 0.01）. After 48 hours of TMZ treatment with 800， 1 500 and 2 000 μmol/l， the relative survival ratio of YTHDF2 shRNA（ except TMZ of 800 μ mol/l） and YTHDF2 shRNA were significantly reduced compared with the control shRNA， and the difference was statistically significant（ P＜0.01）. Survival analysis showed that the overall survival rate of patients with low expression of YTHDF2 was significantly higher than that of patients with high expression of YTHDF2 in MGMT methylation group（ P＜0.05）. In MGMT demethylation group， there was no significant difference in the overall survival rate of patients with low and high expression of YTHDF2（ P＞0.05）. Kyoto Encyclopedia of genes and genomes（ KEGG） pathway annotation results showed that genes with increased expression were mainly enriched in cytokine mediated intercellular interaction， cell cycle and Janus kinase signal transducer and activator of transcription signaling pathway， while genes with decreased expression were mainly enriched in normal neural activity related signaling pathway. GSEA analysis showed that the high expression of YTHDF2 in gliomas was closely related to epithelial mesenchymal transition， cell division and tumor necrosis factor- α mediated by nuclear factor- κB. The results of GO functional annotation showed that in the high expression group of YTHDF2， the high expression genes mainly concentrated in the biological processes related to cell cycle and cytokines. Conclusions RNA methylation recognition protein YTHDF2 can be used as a molecular marker to predict and evaluate the chemosensitivity of gliomas with MGMT methylation.