Sandy culture experiment was conducted at Fac. of Agric., Mansoura University during the two summer   successive seasons of 2010 and 2011 aimed to investigate the effect of N ( 30.0 and 150.0 ppm ) , Na ( 0.0 and 4.0 meq / l) and Ca
( 0.0, 5.0, 10.0 and 20.0 meq / l) in nutrient solution and their interaction   on tomato fruit composition. Combination between the studied factors levels comprise sixteen   treatments which were arranged in a split split block design with 3 replicates . The obtained results can be summarized in the following :- Significant increase in  tomato fruit numbers amounted by 19.72 % in the first season and 19.49 for the second one, where the total yield increases were  18.89 and   18.64 for first and second season, respectively . So fruit weight average  significantly varied due to N level increase from 30.0 ppm to 150.0 ppm ( 29.12 and 15.41 % increase in the first and second season, respectively ) . Sodium application (4.0 meq /l )reduced total yield of tomato fruit by 5.16 % in the first season and a slight increase than that was found in the second one (5.5 % reduction ). N content of tomato fruit was increased from 2.53 to 3.09 % ( 22.13 % increase ) in the first season and from 2.70 to 3.19 % (18.15 % increase) in the second season  due to N level increase in nutrient solution from 30. to 150.0 ppm.    sodium level of 4.0 meq / l in nutrient solution  significantly reduced N, P, and K content of tomato fruits.               Potassium content of tomato fruits was decresed as nutrient solution Ca increase up to  the highest level used (20.0 meq /l ) in both season. 20.0 meq / l Ca decreased  potassium content of tomato fruit by 5.56 and 4.79 %,  compared with control, in the first and second season, respectively  .   Neither  statistically  effect nor constant trend was found on total Ca resulting from  increasing the nitrogen level from 30.0 to 150.0 meq /l in both seasons.  NaCl -Ca took the opposite trend of total calcium, where NaCl -Ca of tomato fruits was increased (5.07 % increase), in the first season and decreased (4.72% decrease) in the second one due to the same increase in N level (from 30.0 to 150.0 meq /l).     HAC-Ca, HCl-Ca and Res-Ca showed a constant trend against N level increase in both seasons.   4.0 meq /l treatment significantly increased all Ca forms in tomato fruit  in both seasons, compared with that of no sodium addition . 10.0 meq / l  treatment  achieved the highest values of total  Ca in both season ( 1726.24 and 1768.78 ppm for the first and second season , respectively ). A concomitant increase in Eth-Ca with increasing Ca level in nutrient solution up to 10.0 meq / l then slightly decreased with 20.0 meq / l treatment in both seasons.                 A strongly increasing trend in NaCl – Ca by increasing Ca level in nutrient solution from 0.0 Ca addition to 5.0 meq /l in nutrient solution (from 883.6 to 1253.48  and from 926.74 to 1222.90 , in the first and second season, respectively  ) .  Lower decreasing rate (from 1396.25 to 1295.65  and from 1330.26 to 1256.98 ppm , in the first and second season, respectively  ) was found regarding to NaCl – Ca form with increasing Ca level from 10.0 to 20.0 meq Ca /l .   In both seasons Ca oxalate was significantly  increased with increasing Ca level from 0.0 to  10.0 meq /l in nutrient solution, these increases appreciated by 276.49 and 275.33 % in the first and second season , respectively . A significant decrease  in tomato fruit calcium oxalate due to increasing Ca in nutrient solution from 10.0 to 20.0 meq /l ( 26.62% and 25.93% increase in the first and second season respectively ) .