Objective To observe the learning and memory ability,oxidative stress,apoptosis morphological changes in the hippocampus,and to explore the effects of hyperuricemia on cognitive function.Methods 51 healthy male SD rats were randomly divided into three groups (17 in each group):Blank group,Distilled water group and Hyperuricemia group.Using the lavage methods of yeast extract combined with ethambntol to establish hyperuricemic model.Morris water maze test was used to measure the learning and memory ability.The levels of MDA,GSH-Px,ASAFR,SOD were measured through chemical colorimetry.Hippocampus morphology structures were observed under the HE staining light microscopy to detect the apoptosis of hippocampus cone cell with TUNEL.Results The average escaped latency and passing platform times of Blank group had no significant difference compared with those of Distilled water group and Hyperuricemia group (all P＞ 0.05).GSH-Px,ASAFR,SOD of Hyperuricemia group ((83.70 ± 5.47) nmol/mg,(606.03±46.61) U/L and (55.05 ± 2.11) units/mg) were increased compared with those of Blank group ((67.28±8.37) nmol/mg,(473.84 ± 57.64) U/L,(45.79 ± 2.05) units/mg) and Distilled water group ((71.96±9.47) nmol/mg,(505.97 ± 47.19) U/L,(46.24 ± 3.65) units/mg) (all P＜ 0.05).Compared with Blank group ((3.19±1.14) μmol/L) and Distilled water group ((3.16±1.43) μmol/L),the MDA of Hyperuricemia group ((1.74±0.45) μmol/L) was significantly decreased (all P＜ 0.05).Form and structures of hippocampal neurons of each group were basically normal under the HE staining light microscopy.Compared with Blank group (CA1:(3.59±0.63) ％,CA3:(5.54± 0.78) ％) and Distilled water group (CA1:(3.25±0.97) ％,CA3:(5.96± 0.82) ％),the hippocampal cells of Hyperuricemia group (CA1:(4.04± 0.78) ％,CA3:(5.95±0.80) ％) also had no statistical differences (P＞0.05).Conclusion Hyperuricemia has antioxidant effect on hippocampal neurons and has no effect on cognitive function and hippocampal neural morphology in rats.