The objectives of this development were to confirm the effect of acetate tow properties on filter pressure drop and to present a useful tool for selecting a suitable tow for a desired filter pressure drop. The Chemical Engineering theory of air flow is applied to this estimation. In our model, the pressure drop of acetate filter is calculated as the sum of friction drag and form drag. To the friction drag, the Fanning equation is applied. To the form drag, the theory of flow resistance for an object in air flow is applied. All the variables in the equation are expressed with items usually used in filters, such as filament denier tow denier, rod length, circumference,..etc. Coefficient of friction drag is determined by actually measured pressure drop value and coefficient of resistance of a column in a right angle flow is used for the form drag coefficient. By applying this theory in a computer program, pressure drop can be estimated accurately, and influence of every factor to pressure drop can be calculated quantitatively in proper dimension and in good agreement with actual measurements. Degree of blooming can be expressed by numerical value. As a result, selection of suitable tow items for desired filter pressure drop became available.