Abstract: Practicability of measuring the catalyst tortuosity factor on a single pellet by chromatography is investigated. Parameters are evaluated by using an integral transform technique and a single perturbation technique. An improved method of moment is provided to treat experimental data. Parameter and variable dependence of the concentrations in the lower chamber is analysed by the asymptotic solutions.An experiment apparatus which can accurately measure the tortuosity factor for many kinds of commercial catalyst pellet by single pellet chromatographic technique is set up. The tortuosity factor of WB-2 catalyst pellet is obtained with the apparatus.