Abstract: Essential oil from lemon peel was extracted by steam distillation method and analyzed by GC- MS,meanwhile,antioxidant and antibacterial activities of essential oil in vitro were explored in this paper. Results showed that 23 volatile constitutes which account for 94.57% of the total essential oil were identified,and the main constitutes were dl- limonene( 42.93%),γ- terpinene( 8.41%),α- Terpineol( 6.39%),E- Citral( 6.09%) and so on.Lemon essential oil showed a good efficiency to remove ·OH with clearance rate reaching to 95.14%; whereas clearance rate of DPPH free radical as high as 34.81% under experimental conditions was far lower than PG and TBHQ.Meanwhile,it could delay the storage period of lard and peanut oil under dosage of 200 mg / kg in spite that antioxidant effect was slightly lower than TBHQ and VE. Antibacterial activity test results indicated that lemon essential oil exhibited definitely activity against the six test microbe,and which showed a best efficiency for Escherichia coli with MIC 0.1μL / m L.