Abstract: Griffing′s method I and 6×6 diallel cross were employed to study the combining ability, reciprocal effects and genetic law of the major characters of winter wheat growing on dryland. The results showed that general combining ability, special combining ability and reciprocal effects of plant height, length of main ear, 1000 grain weight, weight per plant within all the 8 characters studied were significant or high significant difference. The general combining ability and reciprocal effects of the length of ear stem and the rate of efficient ear were significant difference. The reciprocal effect of grains per ear was signficant difference. All three effects of fertile spikelet were not significant. The genetic background for much of characters was dominated by additive genetic effects. The agronomic characters of wheat growing on dryland have high hereditary capacity, while yield characters of that have low hereditary capacity.

Key words: Winter wheat growing on dryland, Combining ability, Hereditary capacity