Objective To investigate the protective effects of melatonin(MT)on early embryo in vitro development of mice after exposure to benzophenone-3(BP-3).Methods Fertilized mouse oocytes at the synge-neic stage were cultured in KSOM culture medium,0.8 μmol/L BP-3 culture medium,and 1×10-7 mol/L MT + 0.8 μmol/L BP-3 mixed culture medium,respectively.The rescue effect of MT on the early embryos developmental potential of BP-3-exposed mice in vitro was explored by detecting the blastocyst rate,gene transcription level,protein expression level,and the degree of DNA damage in the three groups of embryos.Results MT improved the developmental potential of mouse embryos exposed to BP-3 in vitro.Compared with the control group,MT treatment significantly increased the protein expression of ATP5A and ATP5B and decreased the DNA damage(P<0.05).Furthermore,the transcription levels of antioxidant gene Gpx1 and pluripotency related genes Pou5f1 and Cdx2 were significantly up-regulated in MT-treated blastocysts,and the expression of pro-apoptotic gene Bax was decreased.Compared with the control group,BP-3 treatment enhanced the signal intensity of γ-H2AX in blastocysts(P<0.05),while adding MT could effectively alleviate DSBs(P<0.05).Conclusion The physiological concentration of BP-3 exposure has reproductive toxicity,but the addition of appropriate con-centration of MT could significantly improve the in vitro developmental potential and quality of BP-3-exposed early embryos.