〔Abstract〕 Objective The research was aimed at exploring the effects of mandelic acid on the proliferation, apoptosis and migration of H1299 lung adenocarcinoma(LUAD) cells and the related molecular mechanisms. Methods CCK-8 was used to detect changes in the proliferation ability of H1299 cells; Hoechst 33258/PI double-staining assay was used to analyze the apoptosis of H1299 cells; Transwell and migration assays were used to analyze changes in the invasive and migration ability of H1299 cells; Western blot was used to detect the expression of proliferation, apoptosis and migration-related pathway proteins. Results Different concentrations of mandelic acid inhibited the proliferation viability and invasion and migration ability of H1299 cells(P<0.05).Mandelic acid induced high expression of bax and cl-caspase-3 and low expression of p-stat3 in proliferation and apoptosis pathways(P<0.05).In addition, it inhibited the expression of MMP-9 and Vimentin proteins, which were related to invasion and migration(P<0.01). Conclusion Mandelic acid inhibited the proliferation of H1299 LUAD cells and elevated the level of apoptosis, and molecular biological mechanism might be closely related to the decreased activation of stat3 and activation of bax/caspase-3 signaling axis.The inhibition of invasive and migrational ability of H1299 cells induced by mandelic acid was associated with the decreased expression of MMP-9 and Vimentin proteins.