Abstract:The chemical constituents of the essential oils from the leaves of Laurus nobilis L., have been identified both by capillary GC-MS and fused silica capillary GC Kovats retention in,lex of components. From laurel leaf oil, 45 compounds have been identified, among which, 19 compounds such as 1,4-cineole, sabinene hydrate etc. have not been found in the leaf oil previously. This paper studies systematically the constituents of essential oil from dry, fresh leaves, and those of annual, perennial, different district, and reported the changes of the chemical constituents month by month. Results showed that the yield of essential oil and 1,8-cineole content is the highest in July.