This paper is the first issue out of the serial studies on crazing phenomenon caused in chinaware glaze by Mr. Hiroshi Inada, which came out in public on Yogyo-Kyokai-Shi in 1977 and 1978.<br>Through the study, Mr. Inada established quite a new optical method to measure the stress in glaze of chinaware, which was entirely different from the way at that time. And he developed his study with lots of the data gotten from measurement using that method and finally made clear in mechanism how the stress was generated in chinaware glaze.<br>As a result of long study, he has settled up firmly a new technology to protect chinaware as an industrial product from the crazing in glaze.<br>The new method by Mr. Inada is just based on the principle of the retardation, which is able to directly measure and determine the stress in glaze of the final chinaware products. It is more simple and so much capable that should be extremely practical as compared with the previous one.<br>It is the most reliable and direct method of evaluation for the fitness of chinaware body and glaze as well as an effective means of the quality control in the field of industrial chinaware production.<br>Due to the above new optical method, it has turned out possible to measure the stress in glaze caused in the process of heating and cooling.<br>It can be said that he has exactly made clear whole mechanism of craze-generation in chinaware, which used to be estimated judging from curves of thermal expansions of the body and glaze so far. Accordingly he has settled an evaluation method for the fitness of the body and glaze by using the data of the stress in glaze.<br>Furthermore he expanded his consideration with so many data to the study of the effects of stress in the glaze for the reaction of the body and glaze, delayed-crazing of semi-vitreous chinaware, and crazes effected by various conditions of production.<br>In that way, he directed the basic guide to the plan of chinaware materials to prevent the craze.<br>According to his memoirs (FC Report 16, No. 12, 300-311 (1998)), this practical study as above had been done between 1958 to 1960 and the method was practically applied to an actual production field at Nippon Toki K.K. (Noritake Co., Limited). It served there so much to the study on chinaware material and quality control. In this way, after his theory had been put in practice, whole the study was released in public.<br>After that, his new theory and method have been spread widely in the industrial ceramic field in Japan by his own lectures or serial publications in “Yogyo-Kyokai-Shi” and made a great contribution to the advancement of chinaware quality and its productivity.