Objective: To study the adaptability of hygroscopic kinetics curve model of traditional Chinese medicine extract powder. Method : SPSS14.0 statistical analysis software was employed in this study to evaluate the adaptability of the distribution curve of the moisture sorption of six extract powders of traditional Chinese medicine with the coefficient of determination (R2), the residues sum of squares (RSS) and AIC values as index. Result: The double exponential model was the best, first order kinetics model was the second, and the other four kinetics models were the worst. Conclusion: Double exponential model has better adaptability for the fitting of the moisture sorption process of traditional Chinese medicine extract powder.