This research aims to study the naming of the auspicious plant in Thai. Syntactic structures, meaning, and beliefs reflecting from the naming system are emphasized. The data used are from 1620 auspicious plants: 345 plants are from sedge group (medicinal plants) and the other 1275 plants are from Euphoria group (Crown of Thorns). The research finds that the syntactic structures used in plants naming comes in 3 levels: word, phase and group of words, and sentence levels. The most found level is the phrase and group of words level and the second most and the third most found are the word and the sentence levels, respectively. Concerning the meaning, the research finds that there are names carrying auspicious meanings and names carrying other meanings as well. However, there are more names carrying auspicious meaning than those carrying other meanings. The auspicious meanings are divided into 3 groups : 1) the names related to prosperity : 2) the names related to happiness: 3) the names related to security. Most of the names found in the study are related to prosperity. Also, the names carrying other meanings can be categorized into 3 groups : 1) the names related to the information about the plants themselves: 2) the names related to nature and environment, and 3) the names related to individuals (the plants are named after the individuals or named by kinterms). Among these 3 groups, the most found names are the names related to the information about the plants themselves. Moreover, the names of those plants reflect various Thai beliefs which can be classified as: 1) religious beliefs. 2) supernatural beliefs 3) beliefs associated with animals, 4) beliefs associated with jewels 5) belief associated with numbers 6) astrological beliefs 7) beliefs associated with colors 8) beliefs associated with KHAWN (morale). This naming system shows the Thai value in how the Thais name their plants. The plants are named with auspicious meaning, named after the beliefs about the particular plants, and named after the characteristics of the plants. In addition, the naming system reflects 3 Thai values, namely 1) value of wealth 2) value of security in life and 3) value of good healthiness and longevity.
