Abstract: BAG-1 protein is a multi-functional protein,which can interact with a wide range of cellular targets including heat shock protein 70,anti-apoptotic BCL-2 protein,nuclear hormone receptors,growth factors,RAF and components of ubiquitylation/proteasome machinery,and subsequently inhibit cell apoptosis,cellular response to several stimuli.affect the transactivity of nuclear hormone receptor.and to regulate signal pathway and protein degradation.Clinical and laboratory studies have shown that BAG-1 protein is overexpressed in many tumors.and plays a vital role in the pathogenesis and development of tumors as well as the response of patients to chemotherapy.