Aim To investigate the effects of agonist of peroxisome proliferators activated receptor beta/delta(PPAR β/δ) on angiotensin Ⅱ(AngⅡ)-induced hypertrophy myocytes and the changes of expressions of PPAR β/δ in vitro. Methods Hypertrophy in neonatal rat cardiac myocytes(MC) was established with AngⅡ and treated with GW0742.The surface area of MC was analyzed by the aid of NIH Image J software,and the synthetic rate of protein in MC was detected by 3 H-leucine incorporation.mRNA expression of atrial natriuretic peptide(ANP),brain natriuretic peptide(BNP),and PPAR β/δ was measured by reverse transcription-polymerase chain reaction(RT-PCR).Protein expression of PPAR β/δ was detected by immunofluorescence staining.Results Changes induced by AngⅡ of MC were detected,including increases of surface area,mRNA expression of ANP,BNP,and 3 H-leucine incorporation;and decreases of mRNA and protein expressions of PPAR β/δ.Treatment with GW0742 inhibited the changes above.Conclusions The results demonstrate that GW0742,an agonist of PPAR β/δ,inhibits cardiac hypertrophy in vitro and suggest that GW0742 has a potential role in the prevention and treatment of cardiac diseases such as cardiac hypertrophy by activation of PPAR β/δ pathway.