This study was carried out in University of Anbar Alternation location which is located in Abo Ghareeb, the longitude
44 ^o and latitude 33^o. Six genotypes of bread wheat (AlIraq, ALRashed, AboGhraib 3, API 95, AlHashmya and Tmaze2) were crossed in half diallel, in winter season of 2013-2014, to produce fifteen f4 crosses. The parent and crosses were grown in winter season 2015-2016 using randomized complete block design with four replications to determine, general and specific combining ability effects and gene action. Significant differences were found among parents and their crosses for all traits. The variance due to GCA and SCA were highly significant for all studied traits. The cultivrRashed had the best GCA effects for grain yield of single plants. The heterosis and highest SCA effect was expressed in Alrashe×Aboghraib 3  for grain yield, . The variance ratio of GCA to SCA was less than one for all characters, except plant height. The traits were controlled by the dominance effect while the plant height was controlled by additive effect. The values of dominance variance were more than an additive variance for all characters, except plant height. These results reduce the value of the narrow sense heritability for all characters, except plant height. The results reveal that several genotypes could be used to develop new versions of high yield per plant and SCA to produce a better grain yield selects in breeding program.