This work examines one-pillar sermon altars of the Phu Tai ethnic group in six villages in Kuchinarai District, Kalasin Province. It was found that the altars dated back over fifty years. They are different from commonly found altars because they are made from the main pillars of houses. This was a unique belief of the ethnic group by assimilating their animistic beliefs with Buddhism. They believed that constructing a sermon altar was a form of merit making. The six altars were constructed between 1829 and 1940 due to their faith in Buddhism derived from Buddhist history, Buddhist teachings, and their ethnic culture. Most of the altars were partly destroyed by nature and/or through negligence. However, the six altars are still in good condition and are either permanently setup or portable. The objective of this investigation is to conserve this art.