A study was conducted on a 7x 7 diallel set of tomato excluding reciprocals to identify desired parents and its cross combinations which appears high productivity and high quality under conditions in Egypt as well as to gather information on genetic behavior of some traits .The results revealed that both general and specific combining abilities were highly significant for all studied traits .therefore, both additive and non additive gene action were important in the expression of these traits .The magnitudes of additive genetic variances were larger than those of the non – additive variances for plant height ,number of branches / plant ,average fruit weight and TSS % .However ,for other traits ,the dominance gene effects play the major role in the inheritance of these traits. Degree of dominance (Ơ² D/ Ơ² A)^1/2  revealing  the importance of partial dominance and that the additive effects played the major role in the inheritance of the plant height ,number of branches / plant ,average fruit weight, fruit shape index and TSS %.Whereas revealing the importance of over dominance in the genetic control of other traits .In addition both broad and narrow sense heritability values were high for all studied traits ,indicating that all traits were highly heritable .               Heterosis over mid parents or better parents was present in most of crosses for the studied traits. LHT24 and CLN2498D were good combiner for vegetative traits. Peto 86 was the best combiner for number fruits/ plant and total yield/plant .Marglobe is consider good combiner for average fruit weight and fruit shape index .Advantage -2 was best combiner for TSS. Considering mean performances, SCA effects and hererosis, three hybrids LHT24 X Advantage -2, LHT24 X Floradade and Peto 86 X Advantage -2 may be recommended for heterosis breeding after further evaluation.