Western drywood termite, Incisitermes minor, is distributed southwestern USA and northern Mexico. Invasions had been reported to Canada, China, Hawaii and Japan. Incisitermes minor may be introduced through wooden structures. In California and Arizona, it caused economic damage of about $250 million. In September 2023, it was discovered in a house in Changwon-city, Korea and a joint investigation was conducted by APQA and other government agencies. The 16S rRNA sequence was used in the molecular epidemiological investigation to trace the origin of the invasion. Five individuals found in Changwon and 18 foreign sequences collected by NCBI were compared. A total of 462bp of base sequences were compared, and the genetic distance was observed to range from a minimum of 0.000 to a maximum of 0.1791. They were most genetically similar to the California individual in the United States.