The efficiency and benefits of product information of products consisting of natural substances, such as bamboo, charcoal, green tea were explored. The underwear evaluation before/after getting product information was considered through questionnaire survey method. They were asked to guess the price and the natural substances before and after knowing the product information. The subjective responses of comfort and tactile sensation while subjects were exercising in a hot, dry environment were measured experimentally. Their preference and tactile sensations were different after the product information was told. In early running period, the subjects felt comfort mostly in the charcoal underwear, since it absorbed perspiration. In late recovery period, they felt comfort mostly in the bamboo underwear for its quick drying. New underwear products were assumed as higher price than controlled underwear, and after acquiring the product information they guessed much higher prices to the same product, answering the changes in the subjective sensation, too.