AIM: To study the pharmacokinetics of ? Asarone in the volatile oil from Acorus. Tatarinowii Schott. in mice. METHODS: We developed a GC method for ? Asarone determination in blood. The GC system consisted of HP 35 capillary column with Helium as carrier gas, oven starting temperature set at 30℃ , then was raised to 220℃ at a rate of 6℃/min , stayed for 5 minutes, injector temperature set at 250℃ , detector temperature at 320℃ . Injection volume was 2.0 ?L with splitless inject mode. Methanol was used as solvent and ? naphthol as interior standard substance. CONCLUSION: The calibration curve in blood was linear in the range of 0.04?g/ml to 40?g/ml . The minimum detection limit was 0.04?g/ml . The recovery for ? Asarone in blood was 95.3% with RSD 3.92% . After oral administration of volatile oil from Acorus. Tatarinowii Schott., the intracorporal process of ? Asarone in mice accorded with 2 compartment model with 1st order absorption. 6.5min and 93.6min were obtained as t 1/2? and t 1/2? respectively.