The effect of magnesium foliar appliaction on tomato plants was evaluated through two field trials during the two successive growing seasons of 2007 and 2008 at a private Farm (a reclaimed soil), Fayoum, Egypt. To verify this objective, Saria and GLX hybrids of tomato were grown under reclaimed soil conditions and sprayed with magensium (Mg) at the rate of 5, 10, 15, 20 and 30 mgL^-1 (as a chelated form). The obtained results showed the following trends: both of the two hybrids; Saria and GLX showed a different response to Mg foliar application treatments in all studied parameters (growth, yield and chemical constituents). the  foliar application of Mg caused an increase in all the studied characters; growth, yield and quality as well as chemical composition. The response was up to the 15 mgL^-1 level of Mg then decrease again in both seasons (except Mg concentration in leaves). the evaluated parameters were positively affected by the interaction between Mg levels x cvs. Saria cv. which sprayed with Mg at the rate of 15 mgL^-1 recorded the highest values of the most vegetative growth characters; leaves dry weight plant^-1, branches dry weight plant^-1 and leaf area plant^-1 in the first and second seasons while, No. of leaves plant^-1 and canopy dry weight plant^-1 in the first season only. The results revealed that GLX cv. proved superior with highest mean values for fruit yield m^-2 and fruit number m^-2 compared with those of Saria cv. which recorded a high value in fruit weight. Foliar application of Mg increased (comparing to the control) total chlorophyll, carotenoids, N%, K%, P%, Mg% and Ca% in leaves and vitamin C, total acidity, TSS% in fruit of the two hybrids of tomato. The incline in the concentration of the previous mentioned chemical constituents gradually increased as Mg level was increased till 15 mgL^-1 then decrease again (except in leaves which increased up to 30 mgL^-1).   In this respect, all rates of Mg gave higher values with the hybrid of GLX in the most of chemical constituents over the corresponding Saria cv. in both seasons. In comparison to other Mg rates, the two hybrids showed similar trends to Mg at the rate of 15 mgL^-1 where the highest values of all the studied parameters; growth, yield and quality as well as chemical composition (except Mg concentration in leaves) were obtained by both of Saria and GLX cvs. Finally,the presentstudy showed that the best level of Mg foliar application was 15 mgL^-1Mg which, produced the highest yield with a good quality of tomato plants grown under reclaimed soil conditions with the superiority of GLX cv. in this respect comparing with Saria cv.