Aim To investigate the antihypertrophic effects of pioglitazone and its effects on proinflammatory cytokines. Methods Cardiac hypertrophy was produced by abdominal aortic banding(AB) . Pioglitazone(20mg/kg-1 day-1 )was given orally 1 week before operation and continued till 4 weeks after operation, then the rats were killed, part of the heart was used for measurements of left ventricular wall thickness, and the mvocyte diameter, the other part of the heart was used for testing the mRNA expression of proinflammatory cytokines. Result The mRNA expression of proinflammation cytokines Interleukin-1β, Cardiotropin-1 and brain natriuretic peptide (a molecular marker for cardiac hypertrophy) was markedly enhanced in the hypertrophic myocardium of AB rats. Compared with control group, treatment of AB rats with pioglitazone significantly inhibited the mRNA expression of the gene mentioned above,and reduced the increases in the heart weight-to-body weight ratio (4.77 ± 0.25 mg/g vs 4. 23 ± 0.22 mg/g, p< 0.05), myocyte diameter (11.61 ± 1.34 μm vs 10.07± 1.07 μm, p<0.05) and left ventricular wall tliickness. Conclusion Pioglitazone may attenuate cardiac hypertrophy through inhibition of proinflammatory cytokines.