Objective To investigate the effect of YTH domain family protein 2(YTHDF2)on an-giotensin Ⅱ(Ang Ⅱ)-induced hypertrophy and apoptosis of primary neonatal rat cardiomyocytes.Methods The expression level of YTHDF2 was detected in the primary neonatal rat cardiomyo-cytes with or without Ang Ⅱ stimulation(AngⅡ group and normal group).The cells were divid-ed into blank group(transfected with siRNA+PBS),siYTHDF2 group(transfected with siYTHDF2+PBS),model group(siRNA+Ang Ⅱ)and experimental group(siYTHDF2+Ang Ⅱ)to investi-gate the effects of silencing YTHDF2 on the hypertrophy and apoptosis of cardiomyocytes.West-ern blotting and RT-qPCR were used to detect the expression of YTHDF2 at protein and mRNA levels,and RT-qPCR was employed to measure the mRNA levels of myocardial hypertrophic related genes atrial natriuretic peptide(ANP),brain natriuretic peptide(BNP)and beta-myosin heavy chain(β-MHC),and cardiomyocyte apoptosis related genes Bax and B lymphocytoma 2 gene(Bcl-2).The surface area of cardiomyocytes was observed by α-actin immunofluorescence staining.Cardiomyocyte apoptosis was observed by TUNEL staining,and the binding relationship between YTHDF2 and Bcl-2 was verified by immunoprecipitation.Results The expression of YTHDF2 at protein and mRNA levels were significantly higher in the AngⅡ group than the nor-mal group(1.49±0.03 vs 0.97±0.09,1.50±0.08 vs 1.00±0.07,P＜0.05).Compared with the blank group,the surface area of cardiomyocytes was notably enlarged,apoptotic rate was obvi-ously increased,the mRNA levels of ANP,BNP,β-MHC and Bax were significantly increased,and that of Bcl-2 was remarkably decreased in the model group(P＜0.05).The experimental group obtained decreased surface area and apoptotic rate of cardiomyocytes,lower mRNA levels of ANP,BNP,β-MHC and Bax,and increased mRNA expression of Bcl-2(P＜0.05).Conclusion Silencing YTHDF2 can alleviate Ang Ⅱ-induced hypertrophy and apoptosis in primary neonatal rat cardiomyocyte,and YTHDF2 inhibits the expression of Bcl-2 by binding to it.