The mechanism of acute rejection (AR) after liver transplantation is explained as T cells mediated cellular immune response at home and abroad, but in order to achieve long-term survival, it is still necessary to take immunosuppressants for a long time or even for life. Even so, AR still occurs from time to time in clinic, and leads to the loss of transplant liver function in a considerable number of recipients. More importantly, the recipients are also affected by infection, tumor and a series of other adverse reactions and heavy economic burden. Therefore, it is imperative to put forward a new theoretical explanation for the AR mechanism of liver transplantation, and to clarify the internal mechanism of immune rejection of liver transplantation more comprehensively and deeply, and then to develop new immunosuppressants according to the new mechanism. This article reviews the role of humoral immune response mediated by B cells in the AR after liver transplantation.