The fungi cidal effect of four plants extracts namely Chiysanthemum coman urn, Hyo-scyamum muticus, Ocimum basilicum and Solanum nigrum were studied on growth and development of Fusanurn oxysporum which cause senous diseases to members of most families. Among all species tested, O. basiiicum extract was the most toxic to the tested fungus where its essential oil was more effective than petroleum ether, dichioromethane, chloroform and methanol extracts. They have EC5O'S as follows 723.6, 2331.8, 3539.9, 32200.3 and 70923.5 pg/mI, respectively. Aroma chemical constituents of O. basdicurn leaves essential oil were identified by gas chromatography!mass spectroscopy (GCIMS). The major aroma constituents were eugenol (22%) which was the most effective and causes complete inhibition growth at all concentrations, followed by I ,8-cineol (4%) which showed no inhibitory effect and linalool (4%) was completely inhibited growth at concentration of 4000 pg/mI, as they appeared in (GCIMS).