The collection efficiency of fine aerosol particles of a cyclone collector was improved by combining the cyclone with filters. The effects of particle size and inlet velocity on the penetration and pressure drop were studied. Results show that the penetration of the cyclone combined with a 4-mm and a 8-mm fibrous filter for particle sizes between 0.3 to 1.0m was lower than that of the cyclone up to about 20%. The penetration of the cyclone combined with 0.94 and 1.83g stainless steel filter was found to be lower than that of the cyclone up to about 41%. Moreover, the pressure drop of the cyclone combined with a 4-mm and a 8-mm fibrous filter width was 39.9 and 48.9%, respectively, lower. For a cyclone combined with 0.94 and 1.83g stainless steel, the pressure drop was 30.6 and 25.7%, respectively, lower. The improvement of the collection performance, a higher collection efficiency, and a lower pressure drop, is attributed to a change of the collection mechanism from centrifugal force to partial filtration at lower tangential velocity.