To investigate the effect of LianXia Formula Granule on ventricular fibrillation threshold and connexin 43(Cx43)remodeling in myocardial infarction rats.Methods:The model of myocardial infarction was established by ligating the left anterior descending coronary artery of the rat，and the successfully modeled rats were randomly divided into a model group，a Lianxia formula granule high，medium，and low dose group，and a metoprolol group，and a sham operation group.After 30 days of intervention，the ventricular fibrillation threshold was detected by in vivo programmed electrical stimulation; RT-PCR method was used to detect the expression of P38mRNA and Cx43mRNA in the marginal zone of left ventricular myocardial infarction; the density and distribution of Cx43 were detected by immunohistochemical staining; the content of serum TNF was detected by ELISA method.Results:Compared with the sham operation group，the ventricular fibrillation threshold of rats in the model group was significantly reduced，the expression of Cx43mRNA was decreased，the distribution was disordered，the content of serum TNF-α and the expression of myocardial P38mRNA were significantly increased(P<0.01).Compared with the model group，the ventricular fibrillation threshold of rats in the high and medium dose groups of Lianxia formula particles increased(P<0.01，P<0.05)，the expression of Cx43mRNA increased(P<0.05)，the distribution of Cx43 was improved，and the level of serum TNF-α and the expression of P38mRNA in myocardium was significantly reduced(P<0.01).Conclusion:LianXia Formula Granule can raise ventricular fibrillation threshold，and its mechanism is related to reducing inflammation and improving connexin 43 remodeling.