Fibrous materials represent an important product in the application of fibres destined for clothing production, indoor textiles production and technical textiles production. Different kinds of clothing are used in direct or indirect contact with human skin. These types of textiles require appropriate utility properties, mainly suitable heat and moisture transport - physiological properties. This work examines the effect of the geometry of PP fibres on the structure and utility properties of textiles – thermoclothing. The fibers geometry highly influences the heat and mass transfer through textile clothing. Four polypropylene fibers of different cross sectional shapes namely four channel profile, round hollow, round and hollow triangle were used in this work. A relationship between the called shape factors for the different fibers was established. The intake heights were analyzed. It was found that the size of the surface area has an impact on process of processing fibres, determines the penetration of gases or liquids, sorption and diffusion in the fibres. The cross sectional shape of fibers has also influences the heat and mass transfer through textile clothing.