The present investigation was carried out at the Farm of Sakha Agricultural Research Station, during 2012 and 2013 summer seasons. Combining ability analysis was estimated in rice through a 6 x 6 diallel set analysis involving 6 diverse parents for grain yield and its components and grain quality. Eight yield and its component and eight grain quality characters were studied.  Mean square values of parents and crosses and parents vs crosses were found to be highly significant for all characters. Both general and specific combining ability variances were found to be highly significant for all characters, indicating the importance of both additive and non-additive genetic variance in determining the performance of the studied sixteen characters. GCA/SCA ratios were found to be greater than unity for all characters studied except for panicle length, number of filled grains/panicle and gelatinization temperature, indicating that the additive and additive x additive types of gene action were of great importance in the inheritance of all the studied characters except for the three mentioned traits which were controlled by non-additive genetic variance. The genotypes GZ 1368, Sakha106, Sakha 102 and Sakha 103 were good general combiners for most studied characters. Cross combinations involving such parents were superior for most of studied characters. The promising combinations for grain yield along with at least two of yield component characters were GZ1368 x Giza 177, Sakha 106 x Giza 176, Sakha 102 x Giza 177, Sakha 102 x Sakha 106, GZ 1368 x Sakha 103 and Giza 176 x Giza 177. Four crosses Sakha106 x Giza 177, Sakha103 x Giza177, Sakha102 x Giza 176 and Sakha103 x Giza176 showed highly significant and positive SCA for most studied grain quality characters. A greater magnitude of heterosis ranged between 2.38 and 13.88%  was observed in seven crosses i.e. Sakha 103 x Sakha 106, Sakha 103 x Giza 176, Sakha 103 x Giza 177, GZ1368 x Giza 177, Sakha 106 x Giza 176, GZ1368 x Sakha 103 and Sakha 102 x Sakha 106 for grain yield /plant and grain quality characters. The availability of sufficient hybrid vigor in several crosses in respect of grain yield suggests that a hybrid breeding program could profitably be undertaken using these materials. From the foregoing discussion, it may be concluded that the crosses,Sakha 103 x Sakha 106, Sakha 103 x Giza 176, Sakha 103 x Giza 177, GZ1368 x Giza 177, Sakha 106 X Giza 176, GZ1368 x Sakha 103 and Sakha 102 x Sakha 106 can be rated as the best crosses based on their heterosis in most of the studied traits including grain yield. Thus, it can be exploited in subsequent generations to improve most of the studied traits. Four crosses Sakha106 x Giza 177, Sakha 103 x  Giza 177, Sakha 102 x  Giza 176 and Sakha 103 x  Giza 176 could be recommended for growing as hybrid rice.