Objective To investigate the effects of ω-3 polyunsaturated fatty acid(PUFA)on oxidative stress produc-tion and apoptosis in hippocampus of neonatal rats with brain injury induced by lipopolysaccharide(LPS). Methods Forty-eight neonatal Sprague Dawley rats(3 days)were randomly divided into control group,LPS group,ω-3 PUFA group and ω-6 PUFA group,with 12 rats in each group. The rats in the LPS group,ω-3 PUFA group and ω-6 PUFA group were given 0. 6 mg·kg - 1 LPS via intraperitoneal injection,then equal volume of saline,ω-3 PUFA and ω-6 PUFA was immediately given via intraperitoneal injection respectively;while the rats in the control group were all given equal volume of saline. The rats in each group were sacrificed at 24 hours after intraperitoneal injection with saline or fat emulsions to obtain the hippocampus. The levels of superoxide dismutase(SOD)and malondialdehyde(MDA),reduced glutathion(GSH),oxidized glutathione(GSSG) were detected and GSSG/ GSH was calculated. The apoptotic index was measured by terminal deoxynucleotidyl transferase-me-diated dUTP nick end labeling. Results Compared with the control group,the levels of SOD and GSH in hippocampus of rats in the LPS group,ω-6 PUFA group and ω-3 PUFA group were significantly decreased(P < 0. 05),and the levels of MDA, GSSG and the ratio of GSSG/ GSH were significantly increased(P < 0. 05). Compared with the LPS group,the levels of SOD and GSH in hippocampus of rats in ω-6 PUFA group were significantly decreased(P < 0. 05),the levels of MDA,GSSG and the ratio of GSSG/ GSH were significantly increased(P < 0. 05);the levels of SOD and GSH in hippocampus of rats in ω-3 PU-FA group were significantly increased(P < 0. 05),the levels of MDA,GSSG and the ratio of GSSG/ GSH were significantly de-creased(P < 0. 05). Compared with the ω-6 PUFA group,the levels of SOD and GSH in hippocampus of rats in ω-3 PUFA group were significantly decreased(P < 0. 05),the levels of MDA,GSSG and the ratio of GSSG/ GSH were significantly in-creased(P < 0. 05). The apoptotic index in the LPS group,ω-6 PUFA group and ω-3 PUFA group was higher than that in the control group(P < 0. 05). The apoptotic index in the ω-6 PUFA group was higher than that in the LPS group(P < 0. 05). The apoptotic index in the ω-3 PUFA group was lower than that in the LPS group and ω-6 PUFA group(P < 0. 05). Conclusion ω-3 PUFA can alleviate the oxidative stress,and decrease the apoptosis of hippocampus in neonatal rats with brain injury in-duced by LPS. So it has a neuroprotective effect in brain injury induced by LPS.