The field work dealing with this study was conducted during successive seasons of 2019 and 2020 in order to improve synthetic variety "Moshtohor 108". Hybridization were made between 36 male and 4 different females to made design-I as outlined by Comstock and Robinson (1948) to produce 144 full-sib families in the first season. In 2020, 144 crosses were randomly divided into 4 sets and assigned at randomized complete block design with 3 replicates. The data were taken on maturity date, grain yield plant^-1 and its components. Additive (s²A), dominance (s²D) variances, heritability and expected gain from various methods of selection were estimated within the synthetic "Moshtohor 108". Males/set and females/male/set mean squares were significant for all studied traits. s²D was significant and great than s2A for most studied characters. High heritability in broad sense for all studied traits were detected and ranged from 85.83 to 79.79 along with low or moderate narrow sense were detected for all traits except 100-kerenl weight. Predicted genetic advance per cycle for improvement of "Moshtohor 108" were calculated for six methods of selection. High ∆ g % for grain yield plant^-1 were achieved by using methods of test cross, half-sib with selfed seed selection and S2 fill-sib selection and ∆ g % reached 13.87, 8.4 and 8.27%, respectively. From this study, it is possible to improve the variety under study, since large variance within it and presence of additive variation with a medium degree. Thus the yield potential of this variety can be improved.