Objective: To determine optimum extraction process of volatile oil from roots of Valeriana officinalis in Guizhou province and analyze its chemical composition. Method: Volatile oil from roots of V. officinalis was extracted by steam distillation method

distillation time

solid-liquid ratio

soaking time

degree of smash and other factors were investigated with extraction ratio of volatile oil as index

extraction technology of volatile oil from roots of V. officinalis was optimized by single test and orthogonal test.Chemical composition of volatile oil was analyzed by gas chromatography-mass spectrometry (GC-MS). Result: Optimal extraction process of volatile oil was as follows:grinding degree 10-20 mesh

solid-liquid ratio 1∶10

soaking time 4 h

distillation time 5 h;Under these optimized extraction conditions

yield of volatile oil was 5.74%.25 kinds of chemical composition were identified from volatile oil

there was terpene compounds mainly

and it contained olefin

alcohol

ketone

ester

ether compounds

respectively.Bornyl acetate

incense tree by and hom-ene took dominant position

their relative mass fraction were 37.94%

18.52%

10.26%. Conclusion: This optimized technology was stable and feasible

it could be provide scientific basis for industrialized extraction of volatile oil from V. officinalis produce.