Objective To explore the effect of perinatal high fat diet on spatial learning and memory in SD rat offspring. Methods A total of ten pregnant SD rats were randomly divided into control group and high fat diet group,fed with lab chow diet and high fat diet (containing 20% of lard) respectively.After weaning,half of male pups from either group were fed with lab chow and the other half were fed with high fat diet until 12 weeks of age.Then,Morris water maze task was applied to evaluate spatial learning and memory in the pups,and the body weight,the mass of visceral fat and brain were weighted and the level of plasma leptin was measured through ELISA. Results The pups fed with high fat diet from perinatal period until 12 weeks of age showed poorer performance than others in spatial leaning (P＜0.05),but no difference in memory (P>0.05) ability than others;Postweaning high fat diet reduced the body weight and the mass of visceral fat in the pups;Maternal high fat diet during pregnancy and lactation reduced the mass of brain and lowered the level of plasma leptin of offspring. Conclusion Maternal high fat diet during gestation and lactation may impair the development of brain and lower the level of plasma leptin,which could be relative with the cause of the impairment of learning.