Mitogen-activated protein kinases,such as ERK,JNK,and p38,regulate the cell growth,differentiation,apoptosis and cell-cell interaction responding to growth factors,agonists and stress stimuli.Mitogen-activated protein kinases play an important role in the process of the cardiomyopathy and heart failure.Mitogen-activated protein kinase phosphatase-1 is a shock protein to dephosphorylate the mitogen-activated protein kinases.It inhibits the activity of mitogen-activated protein kinases,which is activated by stress stimuli and plays role in the process of heart failure.In this review paper,the roles of mitogen-activated protein kinases and mitogen-activated protein kinase phosphatase-1 were summarized from the in vivo research results of transgenic animal models.