Objective: To analyze the expression of mecp2 gene at mRNA and protein;Cerebral cortex level in the cerebral cortex of the normal Wistar rat throughout development. Methods: We chose the 15th day (E15), 17th day (E17), 19th day (E19) of embryo period, the day of birth (P0), the 7th day (P7), the 14th day (P14), the 28th day (P28) of postnatal period, and adulthood as analyzing time points. The expression of mecp2 gene at mRNA level was analyzed by real time PCR and Northern blot. The expression of MeCP2 protein was analyzed by Western blot. Results: There was one type of mecp2 mRNA transcript (approximately 10 kb) expressed in the cerebral cortex of the normal Wistar rat. The expression level of mecp2 mRNA varied subtly during the development. There was one type of MeCP2 protein (75 000) expressed in the cerebral cortex of the normal Wistar rat. The expression level of MeCP2 protein remained the lowest on E15, from E19 to adulthood the expression levels of MeCP2 protein increased dramatically compared with that on E15. From P7 to adulthood, the differences of expression between two time points were subtle. Conclusion: The expression level of MeCP2 protein increases as the neurons in the cerebral cortex of normal Wistar rat grow mature. This indicates that MeCP2 protein is very important to neuron's maturation, and probably has relationship with maintaining maturation state of neurons.