The purpose of this study was to analyze the content of 73 mission statements published by colleges and universities accredited by the Ministry of University Affairs of Thailand from 1916 to 1999. Data from printed material, the internet and questionnaires to include the mission statement of all of the tertiary education institutions attached to the Ministry of University Affairs were corrected. Following the analysis, the findings are separately checked by team of five experts and the data are presented in the forms of diagrams and tables followed by detailed explanation so that the evolution of mission statement of Thai higher education institutions can be perceived. In the analysis, the 73 Thai higher education institutions attached to the Ministry of University Affairs were grouped according to the institution control classification and Carnegie classification. The analysis of the mission statements is achieved through the analysis of text content and word content from the word profile. It is presented according to the three phases of the establishment of higher education institution so that the evolution of the mission statement can be clearly understood. The main findings are that there are altogether 29 higher education institutions with mission statements whose content comprises all the elements investigated according to the criterial of analysis. Added to this, some of the institutions use the same wording while others use unique expressions that reflect specific types of institutions. In terms of content under investigation, the different assigned roles as perceived by each type of institutions are revealed and the content covers the four main missions of Thai higher education institutions as a whole. Considered in terms of the evolution of the mission statements of Thai higher education institutions attached to the Ministry of University Affairs, their continuity and completion meet the criteria used for all the phases in the analysis. Such qualities are absent in the mission statements of private higher institutions.