I experimented on commercial infant formula in passive cutaneous anaphylaxis inhibition methods. I used several guinea pigs for this experiment. The results obtained from this study were as follows : 1) Commercial infant formula showed positive reactions, while soy-based formula showed negative reactions. 2) The products from different companies showed different reactions respectively The products of "A" company showed low allergenicity compared to the products of "B" company. The Products of "C" company showed the lowest allergenicity. 3) It seemed to be that the differences of allergenicity among the products by various companies were caused by the differences of the materials used, the combination ratio of materials, the heat treatment level, and manufacturing processes., and manufacturing processes.