Sales of conventional cigarettes are decreasing while sales of cigarettes containing capsules are increasing. Demand for twin capsule cigarettes is increasing in the Korean market due to the flavour. When twin capsules were applied in one cigarette, mainstream smoke flavour delivery was evaluated. As ventilation levels and position of capsule were changed, flavour delivery also changed. This research presents the maximum flavour delivery in mainstream smoke. NTM (Non Tobacco Material) was designed by ventilation levels and positions of the capsule within the cigarette. The study design included two ventilation levels (0% and 80%) and two positions of the capsule within the cigarette (mouth section and tobacco section). Combinations of these two materials were made of four cases (0%-mouth, 80%-mouth, 0%-tobacco, 80%-tobacco). In case of low ventilation, a large amount of flavour was delivered by capsule break in tobacco section. In case of high ventilation, plentiful amount of flavour was delivered by capsule break in mouth section. The results were proved by thermal image analysis, sensory evaluation and CFD programs. Which position of capsule break was good for higher amount of flavour delivery in case of different ventilation levels? High ventilation was mouth section and low ventilation was tobacco section.