The objective of this study was to analyze the structure of Hot-Rolled Steel Market in Thailand. This research serves as a clinical support tool, which includes. The future price estimation and borecasting future demand of Thailand’s steel industry. There were several factors such as fundamentals of the steel industry, mardet structure, ability to compete barriers on mardet entry, strategies of the manufacturer and hot-rolled steel of the major countries, which were concluded in this report. The quantitative analysis was used for counting Time Series and Regression analysis. By setting of dependent variable as the consumer demand for hot- holled steet in Thailand, and Independent variables as the amount of finished steel consumption in Thailand, gross domestic product of the steel industry. The analysis was done not only statistical calculate program and the businesssentiment index. But also descriptive analysis based on the situation of the hot- rolled steel market in Thailand.The scope of research to study the results of companies included Sahaviriya Steel Industry Company Limited (Thailand), G Steel Public Company Limited (Thailand) and GJ Steel Public Company Limited (Thailand). The secondary source of data was selected to be used in this study which that came from private and public information. After the researching results shown in the category the oligopoly market concept. The oligopoly market in steel business may caused by high investment and low profit return, therefore less new entry in this market. For the analysis of the gross domestic product and the business sentiment index had linear correlation consumption in the samedirection with the hot-rolled steel sheet in Thailand. Keywords: The Hot-Rolled Steel Sheet