Objective To investigate the expression of m6 A methyltransferase-like protein 14(METTL14)in the hippocampus of depression-like mice,and to provide a theoretical basis for further study of the molecular mecha-nism of depression and new drug targets.Methods 1)Twenty-four male C57BL/6J mice were divided into con-trol group and depression model group.The control group was fed normally,and the model group was kept in single animal cage for 4 months and added with Chronic Unpredictable Animal Stress(CUMS)to establish the depression-like model.2)After modeling,depression-like behaviors in model group were tested using forced swimming test(FST),sucrose preference test(SPT)and tail suspension test(TST).3)Twenty-four hours after completion of behavioral test,the hippocampus tissues of mice were collected,and the expression of m6 A methyltransferase-like protein METTL14 in the hippocampus of mice was detected by molecular biology experiments.Results 1)The mice in the model group showed significant depression-like behavior;2)The expression of MET-TL14 in the hippocampus of the model group showed an increased mRNA expression with the increased m6 A modifi-cation.3)In the model group,the expression of METTL14 in hippocampal CA1,CA3 and DG districts increased and there was neuronal damage found.Conclusions m6 A methylation function has been proved to be more active in the hippocampus of depressed mice.