Objectives: BCS( Bambusae concretio silicae) is used as a traditional medicine in Korea for the incipient stroke. Recent reports indicated that BCS has a neuroprotective effect by anti-convulsion effect. However, it`s mechanism is not well studied. The purpose of this study was to investigate into the molecular mechanism of BCS for neuroprotection in normoxia of cultured rat hippocampal neurons. Methods: BCS (1.0, 2.5, 5.0, and 10.0 ㎍/㎖) was added to culture media (Neurobasal supplemented with B27) on DIV 0, given a normoxia, and the cell viability was measured by typical phase-contrast images of the cultures with 1.0, 2.5, 5.0, and 10.0 ㎍/㎖on DIV 21. Effects of BCS on the expression of various synaptic proteins (GABAB R1, GABAB R2, GlyR, PSD95) were observed by immunocytochemistry showing on DIV 3, 7 and 21. Results: Typical phase-contrast images of the cultures indicated that BCS has a protective effect of rat hippocampal cells in normoxia. The BCS upregulated GABAB R1 after normoxia on DIV 7, GABAA β2/3 on DIV 21 and GABAB R2 on DIV 21. And the BCS downregulated PSD95 after normoxia on DIV 7. Conclusions: The present study showed evidence for the efficacy of BCS in Typical phase-contrast images, upregulation of inhibitory neurotransmitter receptors(GABAB R1) and downregulation of PSD95 which eventually protected neuronal cell death in normoxia.