The effects of coriaria lactone (CL) on gamma-aminobutyric acid (GABA) secretion, glutamic acid decarboxylase (GAD) activity and glutamate (Glu) receptor binding were studied by using cultured neurons, P2 component and synaptic membranes from rat cerebral cortex. It was found that GABA secretion was depressed by CL, the depression rate was 8.3%, 10.6%, 14.5% at 12h 24h 48h respectively. GAD activity was depressed by CL in concentration of 0.15-150 mumol/L. The depression rate was 1.32%, 5.96%, 13.24%, 18.76% respectively. The Glu receptor binding capability was decreased by CL with obvious dose-effect relation in the extent of 2.8-350 mumol/L; the decrease rate was 4.4%, 12.7%, 15.2%, 19.5% respectively. The difference was significant as compared to control (P < 0.01).