The present investigation was carried out at Sakha Agricultural Research Station during 2013/014 to 2015/016 seasons to estimate genetic variance components and type of gene action controlling earliness and yield components of five barley crosses. These crosses used six-population model to determine the intra - and inter-allelic gene interactions controlling the inheritance of earliness and yield traits in five crosses of barley. Mean effect was highly significant for all traits in all crosses. Dominance × dominance was greater in magnitude than other components in most studied traits, indicating that these traits were greatly affected by dominance and its non-allelic interactions. Significant and highly significant desirable percentages of heterosis relative to mid and better parent were exhibited for grain filling period in crosses no. 1, 3 and 5, plant height in crosses no. 1 and 5, no. of grains/spike in crosses no. 1 and 4, no. of spikes/plant in crosses no. 2, 3 and 4 and grain yield/plant in cross no. 4. Broad-sense heritability values were high in all crosses for all studied traits. Narrow-sense heritability and genetic advance ranged from low to medium in most cases due to the opposite directions of dominance and dominance x dominance effects. Generally, the most promising crosses were the two crosses 1 and 5 for earliness and crosses no. 2, 3 and 4 for grain yield found to be higher in magnitude, which had high genetic advance associated with high heritability and would be of interest in breeding programs for improving barley.