The purposes of this dissertation are to study the actions of the Thai state which had affected the Chinese from the period of the revolution in 1932 to Prime minister Phibul Songkhram’s administration (1938 - 1944) ; to understand causes and factors which the Thai state did on the Chinese ; and to understand the nature of the Thai State’s actions on the Chinese as well as the result as such actions. The assumption of this study is that, due to the Thai state in this period had the “Nationalism” idea, it treated the Chinese more strictly and seriously. Since the Thai state’s actions on the Chinese were various and depended on the state’s attitude and policy, the Chinese reacted and reflected differently on the benefit of each Chinese. The findings reveal that Thai state from 1932 revolution to the era of General Piboonsongkham treated the Chinese more strictly and seriously because the Thai state during this period had the ideas of “Nation” and “Thai Nationalism” in the different way ; the Thai state employed the “Thai Nationality” to distinguish the “Thai”, from the Chinese. The Chinese were not only unable to acquire the same rights as the Thais, but also were they affected from the Thai state’s Economic Nationalism” policy which aimed to decrease the role of Chinese in Thai economics, which aimed to decrease the role of Chinese in Thai economics. Futhermore, the fact, that the Thai state considered the Chinese as the seriously unresolved problem because of their quality, their domination on economics, and their “Chinese Nationalism” raising which are difficulties on harmonizing the Chinese with Thai society. However, the Thai state during that time did not treat all Chinese in the same way. It was strict to the Chinese in political, flexible to the Chinese in economics, and almost did nothing to the Chinese in social and cultural ways. According to the said action, the Chinese’s reactions were dinided into 2 main groups which were the group expressing “Thai" and the group maintaining character of the Chinese in politic.