Aim To investigate the protective effect of moderate exercise training on isoproterenol-induced cardiac hypertrophy and the potential mechanism. Methods Thirty-two SD rats were randomly assigned to following groups:control group, isoproterenol group, isoproterenol plus exercise training group and exercise training group. Isoproterenol was injected intraperitoneally for two weeks to create the cardiac hypertrophy model. Rats were forced to swim for 1 hour with nothing attached to the tail,6 days per week for 4 weeks. Heart mass index (HMI) and left ventricular mass index (LVMI) of rats were calculated using weighing method. Surface area of cardiomyocyte was detected by HE staining.The mRNA expression levels of atrial natriuretic peptide (ANP), brain natriuretic peptide(BNP), transforming growth factor-β1(TGF-β1), tumor necrosis factor-α(TNF-α) and interleukine-1 beta (IL-1β) were measured by Real-time PCR and the proteins expression of p65 and IκB were measured by Western blot. Results Compared with the control group, isoproterenol group showed the significantly increases of HMI, LVMI, surface area of cardiomyocyte,mRNA levels of ANP, BNP, TGF-β1, TNF-α, IL-1β and the protein expression of p65 in nuclei. Whereas the expression of IκB was decreased. Compared with isoproterenol group, isoproterenol plus exercise training group decreased HMI, LVMI and surface area of cardiomyocyte. In addition, isoproterenol plus exercise training group significantly down-regulated mRNA expression of ANP, BNP, TGF-β1, TNF-α and IL-1β and p65 protein expression in nuclei while increased the protein expression of IκB. Conclusion Moderate exercise training attenuates cardiac hypertrophy induced by isoproterenol via NF-κB signaling in rats.