OBJECTIVE： To investigate the effects of Xiaosuanzao decoction on spontaneous motion and sleep time in mice， and to study its disassembled formulation. METHODS： Seven ingredients of Xiaosuanzao decoction were selected as the influential factors， including Ziziphus jujuba， Poria cocos， Ligusticum chuanxiong， Anemarrhena asphodeloides， Glycyrrhiza uralensis， Zingiber officinale and Cortex cinnamoni. Two levels of with or without were designed for each factor， and the experiment was arranged according to L8（27） orthogonal test table. The effects of Xiaosuanzao decoction and each ingredient on spontaneous motion within 2 min and sleep time induced by superthreshold dosage of pentobarbital sodium were compared by visual analysis method and analysis of variance. RESULTS： Z. jujube and A. asphodeloides were the main active ingredients of Xiaosuanzao decoction on spontaneous motion； Z. jujube was the main active ingredient of Xiaosuanzao decoction on sleep time induced by superthreshold dosage of pentobarbital sodium. CONCLUSIONS： Xiaosuanzao decoction can inhibit spontaneous motion and prolong sleep time induced by superthreshold dosage of pentobarbital sodium， and Z. jujube is the main ingredient of Xiaosuanzao decoction.