The heterosis of eleven Characters of maize in a set of diallel crosses (including one set of F₁ and parents) among four maize cultivars from each of three geographical regions—France, Japan, the Northeast of China was studied.Path analysis was estimated on the basis of stepwise regression method.The results showed that geographical source of variety may be used as a index that measure heterosis and genetic diversity. Heterosis was in close relationship with geographical source.The heterosis of different endosperm types was greater than that of same endosperm types.The correlation and path-coefficiet analysis showed that the heterosis of yield per plant was in close relationship with the heterosis of eight characters.The yield per plant of hybrid was in close relationship with seven characters.The order of the greatest direct action contributed to heterosis of yield per plant was the heterosis of 100-kernel weight, diameter of car, number of kernel per ear.The order of the greatest direct action contributed to yield per plant was number of kernel per ear, 100-kernel weight and diameter of ear.