Background/Aims: Electroconvulsive therapy (ECT) is an effective treatment modality for severe psychiatric disorders. Many studies have suggested that the therapeutic efficacy of ECT can be attributed to the structural and functional readjustment of the brain cells, which is mediated by differential gene expression in the brain. The aim of this study is to understand the molecular mechanism of ECT. Methods: We used microarray-based gene expression profiling technology and real-time quantitative PCR (RT-qPCR) to screen differentially expressed genes in the brain in a rat model of ECT. Results: Four upregulated and three downregulated genes were identified in this study. The 4 upregulated genes are S100 protein, beta polypeptide (S100b), S100 calcium binding protein A13_predicted (S100a13_predicted), diazepam-binding inhibitor (Dbi), and YKT6 homolog (S. Cerevisiae) (Ykt6), respectively; while the 3 downregulated genes are basigin (Bsg), histidine triad nucleotide binding protein 1(Hint 1), and neural precursor cell expressed, developmentally downregulated gene 8 (Nedd8), respectively. Conclusion: In view of the neurobiological function of these genes and their relevance to mental disorders, repeated ECS can affect gene expression involved in the neurotransmission and synaptic plasticity, which may account for the clinical effects of ECT.