Beauveria bassiana (Biofly); Profenofos (Selecron 72% E.C) and Insect growth regulator (Admiral) as well as Natur'l oil were used against whitefly.  Bemisia tabaci (Genn.) on tomato leaves in Fayoum district, Fayoum Govenorate.  Results indicated that Profenofos (Selecron 72% E.C) and Natur'l oil exhibited the highest reduction in population (after 2 day initial) during two seasons.  While, Insectgrowth regulator; (Admiral) and (Beauveria bassiana) (Biofly) exhibited the highest reduction as residual effect (after 5-7 days) during 1998 and 1999 seasons. The highest reduction in the incidence of Ascorbic acid was obtained with Profenofos (Selecron 72%) while Ascorbic acid increased in case of by (Beauveria bassiana)  (Biofly) treatment.