〔Abstract〕 Objective To study the function and molecular mechanism of the acetylation of malic enzyme 2(ME2) in the proliferation of malignant glioma U87 MG cells. Methods Based on the conserved sequence and combined with the mass spectrometry database, the acetylation modification sites of ME2 were predicted, point mutants were constructed, transfected cells were transfected, and the modification sites were determined by IP and Western blot. The wild-type and mutant of ME2 were transfected into 293 T cells and purified to detect the effect of acetylation on ME2 enzyme activity. The effects of deacetylate Sirtuins 3(SIRT3) on the activity of ME2, ROS and NADH were detected through co-transfection, purification, combined with enzyme activity experiment. After knockdown of endogenous ME2 with shRNA in U87 MG cells, the effects of ME2 acetylation on cell proliferation were detected by stable ectopic expressing wild type ME2 and mutant, which was verified at the animal level by tumor formation in nude mice. Western blot was used to detect the difference of the acetylation level of ME2 in the clinical samples of malignant glioma. Results Results showed that K156 was the main acetylation site of ME2, which inhibited the activity of ME2 and the proliferation of U87 MG cells. SIRT3 deacetylated ME2, improved its activity, thus promoting the formation of NADH and reducing the intracellular ROS level. Conclusion SIRT3-deacetylated ME2 can promote the proliferation of U87 MG cells by increasing the activity of its own enzymes, up-regulating the level of NADH and reducing the level of ROS.