Abstract: : Under salinity stress condition, the root distribution of winter wheat would have greatly changed with environmental factors. Routine methods of simulating root distribution would bring more errors. In this study, a model to estimate root density distribution was developed under salinity stress condition by applying genetic algorithm. This model was applied to predict the root density distribution of winter wheat. The results showed that the predicted root density had good agreement with experiment data. By using the model, the root distribution of winter wheat could be gotten with indirect and easier approach.