Long term climate projection at high resolution is a fundamental dataset for climate change studies, especially for assessing the impact of climate change at the local scale. This future climate projection, which provides a scenario of climate for Southeast Asia at 20×20 km resolution up to the end of the 21st century, is a result of a dynamic downscaling process using a regional climate model (RCM) from the Hadley Centre, The Met Office of United Kingdom, to simulate high-resolution climate data for the region based on datasets from the Global Circulation Model (GCM) ECHAM4 – A2 GHG emission scenario. Results from the RCM show that a wide area of Southeast Asia will become warmer and the duration of the warm period will extend substantially in the future, especially in the latter half of the century. Even though warmer temperatures are detected for both daily maximum and daily minimum values, the daily minimum temperature tends to have a higher trend. Precipitation tends to fluctuate in the first half of the century but shows an increasing trend with higher intensity, which will be clearly seen in the latter half of the century where higher precipitation will be observed throughout the region.