This study investigates possible changes of extreme events in global warming over Korea with MM5 downscaling simulation during the period 1971–2100. Frequency distribution of daily temperatures over Korea shows an increase in the mean by about 5.5°C from 1971–2000 to 2071–2100 while change in the variance is negligible. Increasing temperature results in changes in the frequency and intensity of temperature extremes. Under the current climate change scenario, hot events are expected to be more frequent and intense, while cold events will be rare and weaker. The increasing trend of temperature is associated with an increasing trend of precipitation. The increasing trend produces an increase in the number of the days of heavy precipitation as well as the corresponding amount. Better resolved topography in MM5 produces bigger changes in local precipitation than in the temperature field. Consequently increasing tendency is obvious in the northern part of Korea.