The present study was done to test the effect of Pb treatments on secretory tissue and the chemical structure of the essential oils of basil ( Ocimumbasilicum L.). Lead treatments were as follow: 100, 250, 500 and 7500 ppm in addition to control. The exper iment was done on Ocimumbasilicum L. in a greenhouse, arranged as a randomized complete block design with three replications for each treatment for 60 days.The morphological structure of the secretory tissue of basil leaves was investigated, using SEM (scanning electron microscope).The chemical composition of natural products of sweet basil exposed to lead treatments extracted by methanol and n -hexane, was analyzed by gas chromatography coupled with mass spectrometry (GC –MS). The Results revealed the presen ce of organic aldehyde, diterpenes, monoterpenes, and phenolic compounds in addition to unknown substances. Compounds in the hexane fraction included camphor, 1,8 -Cineol, L-,alpha-Terpeniol, Eugenol, Methyl Eugenol, Beta Elemene, Pachoulene, gamma Cadinen e, 9,12,15 -octadecatrienoic acid,methyl ester, Delta Cadinene, Linolenic acid β- cadinene,stearic acid, and an unknown substances . Compounds in the methanol fraction included furfural, 1,8 -Cineol, 4H -pyran-4-one,2,3-dihydro-3,5-dihydroxy-6-methyl, trans geraniol, β -Linalool,L-,alpha-Terpeniol, Alpha -Fenchyl acetate, Eugenol, Methyl Eugenol, 9,12,15 -octadecatrienoic acid, methyl ester, gamma Cadinene, Linolenic acid, β -elemene, bicycle[3.1.1]hept -2-ene,2,6-dimethyl-6-[4-methyl-3-pentenyl]- and unknown substances. Results were concluded that Ocimumbasilicum is tolerant to lead treatments until 200 ppm, so it can be used as alternative crops for Pb enriched soils.