Abstract： Objective To study the effect and the mechanism of apoptosis of hippocampal neural cells induced by the ketamine in Sprague Dawley(SD) rat.Methods Cortical neurons were isolated from newborn SD rats and were divided into control group and experimental group.Control group was given regular treatment and experimental group was treated with ketamine ( 10,20 μmol/L).After 24 h,the index including cell survival rate,apoptosis rate and the expressive rate of phospho-extracellular signal-regulated kinase ( P-ERK),Bax and Bcl-2 were tested by using CCK-8,FCM and Western blot,respectively.Results Cell survival rates were (73.7 ± 1.5 ) ％ and (58.2 ± 2.4) ％ with 10 μmol/L or 20 μmol/L ketamine treatment,which was.significantly decreased ( P ＜ 0.05 )compared with control group(97.2 ± 1.8) ％.Cell apoptosis rates was (24.5 ± 7.4) ％ and ( 34.7 ± 4.9) ％ with 10 μmol/L or 20 μmol/L ketamine treatment,which also was significantly increased( P ＜0.05)compared with control group (4.7 ± 2.3) ％.The expressions of P-ERK and Bax were increased,while the expressions of Bcl-2 was decreased.Conclusion The ketamine can induce apoptosis in SD rat hippocampal neural cells,which might be involved in activating P-ERK and changing the rate of BAX/BCL-2.