This investigation was conducted to study the possibility of improving some tomato traits. In this respect, during successive early summer seasons of 2008 – 2010 at Zifta distract, Middle- Delta Region, a line x tester analysis was made in tomato (Lycopersicon esculentum Mill.) with eleven femal parents (breed lines) and three male parents (testers) to determine the components of genetic variance, gene action and combining ability effects for some growth and fruit characters. All studied traits, i.e., plant height, main stem length, number of primary branches and leaves, early and total yield, as well as, average fruit weight, firmness, total soluble solids (TSS%) and vitamin C content of fruit have closer values of σ²g and σ²p. The G.C.V. and V.C.V%, which was confirmed by the estimated of G.C.V./P.C.V. ratios (ranged from 0.91 to 0.99) and broad sense heritability (h²bs) values (ranged from 0.85 to 0.98),  suggesting less effect of environmental and the large portion of σ²p was due to the σ²g  on these traits. The magnitude of variance due to general and specific combining abilites were highly significant indicating the importance of the additive (σ²A) and non-additive (σ²D) gene actions. However, the ratios of  σ²GCA/ σ²SCA (<1) and σ²A/σ²D (<1) revealed the preponderance of non-additive variance in the inheritance of all the studied traits. The estimated average degree of dominance (0.76 and 0.90) revealed partial and complete dominance for average fruit weight and TSS % content, respectively, while revealed over-dominance (>1) for the remaining traits. The parental lines G.16, S.65, G.30 and the tester G.19 were found to be the most desirable general combiner (they possessed dominant genes) for seven, six, five and six traits, respectively. The cross combinations S.60 x G.19, S.125 x G. 19, G.30 x SSB and G.30 x Peto 86 considered the best specific combinations since showed significant SCA values for five traits. The results also suggested the possibility of improvement of these tomato traits through recurrent selection and hybrid breeding program.