1. Objectives The present study was designed to investigate the effect of Soyangin Hyeongbangdojeok-san(HBDJS) on acute cocaine-induced behavior effect and gene expression in the rat brain. 2. Methods Experimental animals were composed of saline(SAL), cocaine(COC), HBDJS + COC, HBDJS + SAL group. Rats received HBDJS(100, 200 mg/kg, p.o.) 1 h prior to cocaine hydrochloride(20 mg/kg, i.p.) treatment respectively. After cocaine injection, locomotor activity and rearing were measured in a rectangular container equipped with a video camera above the center of the floor for 60 min. In addiction, c-Fos expression in the rat brain was detected using immunohistochemistry 2 h after cocaine injection. And the effect of HBDJS on acute cocaine-induced pERK, pElk, pCREB upstream of c-Fos expression was detected using western blotting and immunohistochemistry 15 min after cocaine challenge. 3. Results The present results show that HBDJS at dose of 200 mg/kg attenuated cocaine-induced both locomotor activity and rearing. Also HBDJS at dose of 200 mg/kg significantly decreased c-Fos expression in the rat brain(nucleus accumebns and striatum). However HBDJS at dose of 200 mg/kg have no effect on cocaine-induced pERK, pCREB, pElK-1 expression. HBDJS is c-Fos expression through ERK-independent pathway. 4. Conclusions. These results suggest that HBDJS may be effective in suppressing the reinforcing effects of cocaine.