Abstract: OBJECTIVE To optimize the extraction process of volatile components of Angelica sinensis (Oliv) Diels, and to analyze the chemical components. METHODS The volatile oil from Angelica sinensis was extracted by steam distillation method, the investigate factors including soaking time, extracting time and the amount of water, and the yield of volatile oil, the relative percentage of Z-ligustilide, the number of compounds and the comprehensive score were used as the evaluation indexes. The optimal extraction process of volatile oil from Angelica sinensis was screened based on the orthogonal design test combined with information entropy method, meanwhile GC-MS combined with NIST database were used for the identification of the components in volatile oil. RESULTS The optimum extraction conditions were as follows:soaking for 2 h, extracting for 10 h and adding 8 times of water. Under these conditions, the extraction rate of essential oil was 0.38%, the relative content of Z-ligustilide was 73.05%, and 37 compounds were identified. And a total of 55 compounds were identified in this experiment based on GC-MS at the same time. CONCLUSION The optimal extraction process of steam distillation method is reproducible, stable and feasible, and the chemical constituents of the essential oil in Angelica sinensis can be characterized by GC-MS, which provide the basis for the quality control and the development and utilization of medicinal materials of Angelica sinensis.