Three sets of data from the field experiments with different wheat( Triticum L. ) varieties and sowing dates in China and USA were used to test the performance of the mechanistic model of wheat development. The results showed that the absolute prediction errors for most phasic and phenological stages ranged within 0 - 5 days, and the root mean square errors were generally less than 5 days. The model was of high accuracy and low error especially for emergence, tillering, stamen and pistil initiation, and heading stages, reflecting an enhanced level of mechanism and prediction.