Transport phenomena of air, moisture, and heat in fabrics are closely related to the comfort performance from the viewpoint of human physiology. For designing and manufacturing a comfortable cloth, therefore, it would be useful to study structural factors affecting the transport phenomena in fabrics. In this study, the worsted yarns were prepared with different twist levels, and then the fabrics were manufactured with different structural designs, and surface finishing. The change in the twist levels of yarn significantly affects air permeability and heat transfer related to comport performance. The results could be characterized in terms of the cover factor and bulk density of fabric, and rationalized on the basis of known concepts.