Abstract: In recent years， mesenchymal stem cells （MSC） have been widely explored in the treatment of liver diseases due to their characteristics of multipotential differentiation and immunomodulatory capabilities. Current evidence has shown that MSC therapy can improve liver function， alleviate fibrosis， and promote hepatocyte regeneration in end-stage liver diseases such as liver cirrhosis and liver failure. However， safety concerns have emerged with the increasing clinical use of MSC. This article systematically reviews the acute adverse reactions and long-term safety of MSC-based therapies for liver diseases. It is shown that MSC therapy has a good overall safety profile， with common acute adverse reactions of fever， rash， and mild allergy， most of which are self-limiting or can be alleviated by symptomatic treatment. No clear evidence of tumorigenesis has been reported in long-term follow-up， but some studies have suggested a potential association between MSC and the development of hepatocellular carcinoma. In addition， the risks of embolism， immune rejection， and infection susceptibility should be monitored continuously. Overall， MSC therapy shows good prospects in short-term efficacy and safety in the treatment of liver diseases， but clinical studies with a large sample size and a long follow-up period are needed to further validate its long-term safety and efficacy.