A full diallel was established in 2006 at Duhok Univ., Iraq, to study heterosis and combining ability for growth, and yield components in four varieties, Early long purple(1),Long purple(2),Black Beauty(3), and Alton kubry (4) of eggplant. The results revealed that F1's exhibited significant heterosis for all traits. The hybrid (3×1) gave the highest heterosis value for plant height and fruit weight. The hybrid (4×2) produced the greatest value for number of branches and early yield plant . Whereas, the hybrid (4×1) was earliest in date of flowering and possessed the highest heterosis in fruit diameter. The parent 2 (long purple) revealed as the best general combiner for most desirable traits . Analysis of combining ability indicated that GCA mean square was significant for all traits, whereas, SCA mean square was non-significant in number of branches ,number of leaves till 1st inflorescence, total and early yield. Specific combining ability results for each hybrid exhibited that 2x4 was characterized with a good specific combining ability for most traits .On the other hand ,there was a significant reciprocal effect's for date of flowering, no. of flowers inflorescence-1 , average fruit weight, no. of fruits plant-1 ,fruit length and diameter which was obviously recognized between the hybrid 3x1 and its reciprocal.