Abstract: Taxol, originally isolated from the bark of Taxus brevifolia, is a very important new anti-tumor drug.Reversed phase chromatography provides a rapid, efficient, and inexpensive method to separate and purify taxol. However, it is very important to scae-up the isolation process in order to obtain a large amount of taxol. From studies on the basic transport phenomena between solid phase and liquid phase, the rate model for non linear liquid chromatography under normal pressure is proposed.The process of taxol separation on C 18 - silica gel column could be described by this model very well.The numerical solution of model agrees well with experimental data.The factors affecting the separation of taxol, including feed concentration,feed rate and column size are investigated.It is confirmed that the mathematical model could be very useful for scaling-up chromatographic operation.