Abstract: To explore the mechanism of the rats' spatial learning and memory enhanced by some CB and TRPV subtype receptors involved in polyunsaturated fatty acids. 56 male SD rats ( early weaning) were randomly divided into seven groups, DHA group, walnut oil group, perilla seed oil group, safflower oil group, α-linoleic acid group, EFA lack group and negative control group. After 8 weeks of gavage, Ethnology test was done by Morris water maze, and determined the expression of cannabinoid receptor subtypes (CB1-2) and transient receptor potential vanillin subtypes (TRPV1-4) m RNA in the hippocampus of rats ' brain with the method of RT-PCR. It showed that the score of the rats fed by kinds of oils in the Morris water maze improved significantly and the m RNA expression quantity of CB1 and TRPV1 of hippocampus of rats significantly increased, while TRPV2 reduced very obviously, and there was no influence on other subtype receptors. It proved that polyunsaturated fatty acids could improve the rats' spatial learning and memory significantly, related with the expression quantity of m RNA of CB1, TRPV1 and TRPV2.