Abstract: Objective To investigate the effect of propofol on myelin basic protein (MBP) expression in oligodendrocytes of SD rats at different developmental stages. Methods This study was conducted in 3-, 7-, 14- and 21-day-old SD rats (40 in each age group). In each group, the rats were randomized equally into control group and experimental group, and in the control group, the rats received an intraperitoneal injection of 25 mg/kg medium-long-chain fat emulsion followed by injections at a half dose every 20 min for 8 h; the rats in the experimental group were given injections of propofolmedium (at the initial dose of 25 mg/ kg) in the same manner. The transcriptional levels of MBP and caspase-3 in the brain tissues were detected by qRT-PCR, and the protein expression of MBP was with Western blotting and immunehistochemistry. Results Compared with those in the control groups, the expression of MBP mRNA was significantly down-regulated while caspase-3 mRNA was up-regulated in 3-, 7- and 14-day-old rats in the experimental groups (P<0.05). The protein expression of MBP in 7- and 14-day-old rats was significantly decreased in the experimental groups compared with the control groups (P<0.05). The expression of caspase-3 mRNA or MBP protein in 21-day-old rats showed no significant difference between the two groups (P>0.05). Conclusion Propofol can down-regulate the expression of MBP at both the mRNA and protein levels in SD rats, especially in those at 7 and 14 days of age.