The objective of this research is to study the hotspot occurrence pattern in January to April and Long-range Transport Contribution on Haze Episode in the areas sharing borders between northern Thailand, Laos and Myanmar. Hotspots or active fire detected by Moderate Resolution Imaging Spectroradiometer (MODIS) onboard of Terra and Aqua satellites, provided by NASA's Fire Information for Resource Management System (FIRMS) were used to represent open burning locations in the region. The daily backwardtrajectories in March 2014 to 2016, obtained from PM10 measurement station in Chiang Rai province was brought toanalysis using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT4) model. In the result, the hotspot occurrence has similar patterns. Highest number of hotspot was found in March, April, February and January, or 51, 31, 12 and 5 percent of the total number, respectively. The highest hotspot number was found in Myanmar, then Laos and Thailand, or 51, 28 and 21 percent, respectively. Backward trajectoriespatterns mainly moved across the south-western part of the study area, where hotspots were frequently occurred. Consequently, smoke haze problem in the province was influenced by burning at the upwind regions where PM10 was steadily accumulated until reaching the station. Obviously, the smoke problem in northern Thailand and its neighbours is boundless. Therefore, solving this regional problem by reduce burning activities in one country is insufficient. Collaboration between countries is necessary. Active sustainable land use, reduce burning activities after harvesting and maintain the sustainability of the natural resources and environment should be conductedIntroduction.