At present, allogeneic hematopoietic stem cell transplantation is required to cure acute myeloid leukemia except M3, but some patients cannot be transplanted due to the limitation of donor source and economic condition. The current view is to observe until relapse and then treat. Most of the patients will relapse and the treatment effect is poor after relapse. Some places use IL-2 maintenance therapy, but the efficacy is not sure. Huang Dayong of the Department of Hematology at Beijing Friendship Hospital published an article on the use of histamine dihydrochloride in combination with IL-2 maintenance therapy for acute myeloid leukemia, with better efficacy. The FDA and the EU have recently approved the marketing of histamine dihydrochloride (Ceplene) injection for sustained remission and prevention of relapse after initial remission therapy in adult patients with acute myeloid leukemia (AML). It should be administered in combination with low-dose interleukin-2. It has been approved for marketing in 27 EU member states as well as Iceland, Liechtenstein and Norway. The approval of histamine dihydrochloride injection was based on the results of a pivotal phase III clinical study in 320 patients in combination with interleukin-2: complete remission significantly reduced relapses in patients with AML. The proportion of patients treated with the combination of histamine dihydrochloride injection and interleukin-2 who were long-term leukemia-free was greater than 50%. Moreover, the product was well tolerated by patients. Studies have shown that it reduces oxygen production from autophagocytes, inhibits nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, and activates NK cells and T cells. The drug has been genericized by Sinopharm and is being used as a national class 3.1 drug for clinical observation in several hospitals in China, free of charge. The enrollment requirements are 18-60 years old, complete remission of acute myeloid leukemia, and within 6 months after 6-8 courses of consolidation therapy.