This current dissertation is focused on the investigation of the diffusion and permeation properties of low molecule volatile organic substance through elastomer and its micro- and nano- composites. The tert-butyl-benzene (t-BuPh) was used as model substance in the study.In order to carry out the investigation quantitatively, two test methods were applied. An in-house developed and self-constructed two-chamber permeation apparatus was used mainly for the diffusion and permeation measurements. The ATR-FT-IR spectroscopy was utilized as a reference method to examine and correlate the twochamber permeation method.Several different kinds of neat elastomers containing varying molecular structures and chemical properties - BR, SBR, EPDM, NBR, and HNBR - were investigated as first. The influence of the polymer constitution, the "free-volume", the polarity, the chain flexibility, and the elastomer cross linking density on the diffusion and permeation behavior of t-BuPh was studied and evaluated systematically.