A mathematical model for modeling solid-liquid extraction from plants was developed. Two extraction systems were investigated: tamarind seed coat-ethanol and green tea-ethanol. All models were fitted to experimental data and the results were compared. It was found that the model neglecting diffusion transport gave a better prediction than the theoretical model, however, the kinetic coefficient of the process cannot be obtained from this model. When comparing results of neglecting and considering external mass transfer resistance, it was found that both models can be used to predict the extraction yield reasonably well with the same range of mean deviation value.