An improved CFD model of gas flow and particle interception in a fiber material which fiber size is Y-shape was developed in this work. The porous medium model was used to build the model of the whole size of fiber filter medium. Mixture model was adopted. The algorithm of particle interception in the whole size of fiber filter medium was derived and UDF(User Defined Function) that described kinds of particle filtering mechanisms in filter fibrous media was added to the Fluent default conservation equation as source term for simulation. The inertial resistance of the filter was taken into consideration, which provided a more precise measurement of the smoke flow and the particle interception in the filter under higher smoke speed conditions. The commercial software, Fluent 6.3, was used to simulate the smoke flow and particle interception in the filter in a single suction. The velocity and pressure profiles of smoke or nicotine particle in the filter, as well as nicotine particle volume fraction profile were well simulated. Finally, the comparisons of nicotine particle filtration efficiency between Fluent simulation results in this work and experimental results, as well as the model prediction in the literature were made to validate the simulation model. The comparisons showed that the particle entrapment model from simulation results was in good agreement with that from the experimental results. In addition, the Fluent simulation results are closer to reality both at the beginning and the end of the smoke process comparing with the model predicted results in the literature. An improved CFD model of gas flow and particle interception in a fiber material which is developed in this work. The porous medium model was used to build the model of the whole size of a fiber filter medium. The algorithm of particle interception in the whole size of fiber filter medium was derived and UDF (User Defined Function) that described kinds of particle filtering mechanisms in filter fibrous media was added to the Fluent default conservation equation as source term for simulation. resistance of the filter was taken into consideration, which provided a more precise measurement of the smoke flow and the particle interception in the filter under higher smoke speed conditions. The commercial software, Fluent 6.3, was used to simulate the smoke flow and particle interception in the filter in a single suction. The velocity and pressure profiles of smoke or nicotine particle in the filter, as well as nicotine particle volum Finally, the comparisons of nicotine particle filtration efficiency between Fluent simulation results in this work and experimental results, as well as the model prediction in the literature were made to validate the simulation model. The comparisons showed that the particle entrapment model from simulation results was in good agreement with that from the experimental results. In addition, the Fluent simulation results are closer to reality both at the beginning and the end of the smoke process comparing with the model predicted results in the literature.