Background. Most researches related to traditional Chinese medicine (TCM) formula Xiaoyaosan decoction focused on antidepressant. However, the role of this decoction improving anxiety-like behaviors hasn’t been known well. Objective. To evaluate the effects of TCM formula Xiaoyaosan decoction on anxiety-like behaviors and whether JNK signal pathway was involved. Methods. Rats were divided into 5 groups (n=8): control group (deionized water, p.o.), model group (deionized water, p.o.), SP600125 group (surgery), Per se group(surgery), Xiaoyaosan group (3.854g/Kg/d, p.o.). 1% DMSO citrate buffer solution (2μl/ventricle/d) and SP600125 (10μg/ventricle, 2μl/ventricle/d) were separately bilaterally intracerebroventricular injected in two surgery groups. Except for control group, the other four groups were given 14 days Chronic Immobilization Stress (CIS, 3h/d). On day 15, all rats were tested body weight and subjected to elevated plus maze (EPM) and novelty suppressed feeding (NSF) tests. At last, JNK signal pathway indexes, including P-JNK, JNK, P-c-Jun and Cyt-C, were examined. Results. After modeling, body weight and behavioral analyses of model rats indicated this modeling method induced anxiety-like behaviors. P-JNK, JNK, P-c-Jun were also found changes in hippocampus of model rats by western blotting and qRT-PCR methods. After 14 days treatment of Xiaoyaosan and SP600125, body weight, behaviors and P-JNK, JNK, P-c-Jun were modified. But there was no significant difference in Cyt-C. Conclusion. Xiaoyaosan can improve anxiety-like behaviors induced by chronic immobilization stress, which might be related with JNK signal pathway in hippocampus. These finding not only help to understand the actions of the Xiaoyaosan, which may result to the inhibiting JNK signal pathway in hippocampus, but also provide new evidence for the clinic use of the Xiaoyaosan for the treatment of anxiety.