Thai vegetarian festival is celebrated on the ninth lunar month of Chinese calendar in every year. At the beginning, in Thailand, this holiday was not shown in history. It has been passed from old Thai-Chinese Buddhists to new generations, and started in the Southern Thailand. Initially, Thai-Chinese people were the first group to create vegetarian food in order to make virtue and save some animal life that was killed for food. Later, the vegetarian food became famous and known in Thai society. Currently, many Thai people realized that vegetarian food is helping them to have the healthy life. Therefore, they created Thai vegetarian festival, called “Tad-Sa-Karn-Kin-Jay”, that begins in late September and lasts nine days.