This research took from the work of Kohli and Morey in the economics literature to apply a quality derived market share demand function to the international wheat market. Specifically, a Japanese wheat import demand market share model was derived using data for Hard Red Winter, Hard Red Spring, Canadian Western Red Spring, and Australian Standard White wheat. Results indicate that the four wheat classes analyzed here are relatively good substitutes for each other, the own-price elasticity for each wheat class is elastic, and the own-characteristic Protein elasticity for Hard Red Winter 13% protein wheat increased over the period analyzed.