The research was carried out on the effects of 7 agronomic characteristics of maize hybrids on their grain yielding stability, based on regional test materials of summer corns in North China, by using the correlation analysis between regression coefficient and characteristics. The results showed that most agronomic characteristics have negative relevance with yielding stability of hybrids. The most important factors are rows per spike and 1000 grains weight, while spike position and its length、plant height and grains per spike have little relevance. In the practice of breeding, such measures as enhancing selection of those characteristics which have little effects on yielding stability but great effects on grain yielding, properly lowering the height of spike position and increasing grains per spike, are all helpful to improve yielding stability of maize hybrids.