A half diallel set of crosses among six highly diverse barley (Hordeum vulgare L.) genotypes were evaluated at Karahta Research Station, General Commission of Scientific Agricultural Research (GCSAR), during 2010-2011 and 2011-2012 seasons to study heterosis, potence ratio, correlations among traits and path coefficient analysis for number of spikes per plant, number of grains per plant, number of grains per spike, biological yield ,and grain yield per plant. Heterosis effects for seed yield ranged from%-89.52 (T-6669×S-6303) to%16.99 (Arabi abiad mohsan×S-6689) and from%-49.94 (L-6711×S-6689) to %-1. 35 (Arabi abiad mohsan×S-6689) relative to mid and better parents respectively. Potence ratio values ranged from 1.14 (number of spikes per plant) to 3.50 (biological weight) indicating that non-additive gene action was more important in controlling all studied traits. Correlation coefficients among traits indicated that seed yield was positively and significantly associated with each of number of spikes per plant (0.289), number of grains per plant (0.832), number of grains per spike (0.587), and biological yield (0.708) traits. Path coefficient analysis indicated that number of grains per plant trait had high positive direct effects on grain yield.