[Objective] The aim was to study the chemical component of volatile oil of garlic in different districts.[Method] GC-MS was used to analyze the composition of the garlic volatile oil in Guiyang,Guizhou Majiang,Shandong,Yunnan and Chongqing and the HPLC method was used to assay the content of garlicin.[Result] Garlicin in different essential oil had the highest content but varied a lot.The sampling amount of garlicin between 0.562 and 2.810 μg was in a good linear relation(R=0.999 2,n=5) with peak area,the average recovery rate was 99.39,RSD=1.76%.[Conclusion] GC-MS can be used to analysis the composition of essential oil quickly and effectively.The liquid chromatographic analysis of garlicin was simple,reliable and reproducible.The study provided the theoretical basis for selecting garlic in garlic flavor oil production and improving quality of garlicin oil. [Objective] The aim was to study the chemical component of volatile oil of garlic in different districts. [Method] GC-MS was used to analyze the composition of the garlic volatile oil in Guiyang, Guizhou Majiang, Shandong, Yunnan and Chongqing and the HPLC method was used to assay the content of garlicin. [Result] Garlicin in different essential oil had the highest content but varied a lot. The sampling amount of garlicin between 0.562 and 2.810 μg was in a good linear relation (R = 0.999 2, n = 5) with peak area, the average recovery rate was 99.39, RSD = 1.76%. [Conclusion] GC-MS can be used to analyze the composition of essential oil quickly and effectively.The liquid chromatographic analysis of garlicin was simple, reliable and reproducible. The study provided the theoretical basis for selecting garlic in garlic flavor oil production and improving quality of garlicin oil.