This study was aimed at making a model which predicted olfactory sensation. Firstly, it was conducted the experiment, which odor was exposed to subjects constantly and subjects evaluated odor, to investigate the olfactory adaptation process. As a result, it was turned out odor intensity decreasing exponentially as time. Secondly, validity of the previous theoretical model ( Osako,1991 ) was investigated by comparing the evaluation. As a result, it was found out that the validity of the previous model might be better in the case discriminating the adapting intensity from the after adapted.