Abstract: OBJECTIVE To investigate the effects of propofol and corticosterone on the expression of phosphorylated Ca²⁺/calmodulin-dependent protein kinaseⅡ(pCaMKⅡ) and cellular structure in hippocampal CA1 region. METHODS Thirty-six Wistar rats (21-day-old) were randomly divided into 3 groups: control group; propofol group; propofol+corticosterone group. Rats were received intraperitoneal injection of 10 mL·kg^-1 normal saline, 100 mg·kg^-1 propofol or 100 mg·kg^-1 propofol+ 10 mg·kg^-1 corticosterone for 8 consecutive days, respectively. In each group, six rats were selected at random for detection of the expression of pCaMKⅡ in hippocampal CA1 area by immunohistochemical assay and the rest were used to observe the neuronal ultrastructure with transmission electron microscope. RESULTS The expression of pCaMKⅡ in hippcampal CA1 neurons was significantly down-regulated in propofol group and propofol+corticosterone group, compared with that in control group. Electronic microscopic analysis showed that the ultrastructural of hippocampal neurons were damaged in both propofol group and propofol+corticosterone group. CONCLUSION Repeated propofol administration can reduce the expression of pCaMKⅡ, damage the structure of neurons. The combined application of propofol and corticosterone aggravates this effect.