Abstract: Some wells experience proppant flowback after fracture treatment in Xinjiang Oilfield. Loss of proppant from the fractures limits fracture conductivity and impairs the effectiveness of fracture treatment. This paper develops a new prediction model of proppant flowback. Using this new model, the trend of proppant flowing into wellbore from fractures can be predicted and proper treatment can be taken during treatment. While developing the new model the authors took rock mechanics, reservoir fluid, hydraulic fracture and proppant into consideration. Fracture conductivity and formation permeability determine the percentage of the total flow produced through the fracture. When developing frac-ture critical rate model, the authors firstly deduced theoretic critical flow rate, and then corrected the critical rate considering fracture width, closure stress and proppant. The application of the model to fractured wells implies the results of model are in accordance with production.