The present investigation was designed to study combining ability and gene action for yield and yield components in flax under two plant distances. This was achieved via evaluating six parents; P₁ (Sakha 1), P₂ (Giza 7), P₃ (S.2419/1), P₄ (S.16), P₅ (S.22), P₆ (Sakha 3) and their 15 F₁,s progenies under two distances (5 and 10 cm) between plants in a randomized complete block design with three replications at Sakha Res. Station at Kafr El-Sheikh Governorate during 2008/2009 and 2009/2010 growing seasons. The collected data indicated that the additive effects were more important than non-additive effects for eight characters under study, revealed that the inheritance of these traits were mainly controlled by additive effects of genes. On the other hand, non-additive genetic effects were much more influenced by the two distances between plants than additive effects in number of basal branches, 1000-seed weight and number of seeds per capsule. In contrast, additive genetic effects were more influenced by distances between plants than non-additive effects for straw weight, seed weight and number of capsules per plant. P₃ exhibited significantly positive GCA effects for straw weight, number of basal branches, seed weight, number of capsules per plant and 1000-seed weight. Therefore, using this parent in hybridization programs may result in isolating desirable segregates for these characters. For straw traits, two crosses involved high x high general combiner parents, one cross (P₁xP₂) for plant height and other cross (P₂xP₃)for technical stem length as well as P₃xP₆ (high x low general combiners) for straw weight per plant. For seed traits, two crosses, P₄xP₅ and P₄xP₆ exhibited high SCA effects for 1000-seed weight and included low x high general combiner parents. Therefore, it could be concluded that these crosses are suitable in breeding for increasing the above-mentioned traits.