Air quality in a car's cabin, as well as the indoor air quality in the residential environment, has became an important problem in our contemporary pleasant daily life, because it is concerned with safety and comfortable driving.

This paper introduces the instrumental gas analysis method and the sensory evaluation method with the air quality in a car's cabin which we adopt at present, and also discusses the factors which influence the air quality in a car's cabin.

Among these factors, the following ones are explained.

1. Odor and volatile compounds evolved from the interior parts and materials of new cars.
2. Vehicle-emitting volatile compounds and NO₂ as streaming compounds and odorants from the ambient air in the driving area
3. Odor evolved from air conditioners
4. Carbon dioxide, volatile compounds from breath and environmental tobacco smoke evolved from passengers.

Finally, this paper discusses the future aspect of the air quality in a car's cabin. �@

�@