A method of plotting the practical drying curve for a dryer is presented here.First the empirical drying formula for a definite material, such as the granular aminoplastics,is setted up by using regression analyses for a large number of experimental data obtained in different constant conditions. Then the practical drying curve for that material is gived conditions is established according to the empirical formula. It would be utilized to improve the technique of drying processes and to optimize the design of diring equipments.