At the 1996 CORESTA meeting the findings that smoke passes mostly through the center in ventilated filters were presented in our previous study on "Cross-sectional smoke distribution and computer simulation for smoke flow analysis in cigarette filters". As a series of our study, this paper is to demonstrate smoke (gas phase) distribution and smoke flow analysis using a regular dual filter and several model filters with different geometric structures in the center and on the periphery. Trials are also made to visualize smoke flow at the filter exit with a high-speed video in the smoke wire technique. The results of nicotine- and gas phase- distribution and smoke flow are shown in this paper together with the usefulness of smoke-flow visualization as a tool of filter characterization.