In the beginning of 2008, southern China had experienced extreme low temperature, heavy rain, snow, and freezing weather. This extreme weather had impaired the southern area power grid greatly and threatened the security and stability running of power system and power supply. The paper introduces the China southern area power grid basic disaster situation. Based on the China southern area power grid characters and the disastrous weather characters, it reviews the whole accident process of the 500kV main power grid in the snow disaster. Then summarizes the typical characteristics in the disaster of China southern area 500kV main power grid, and reveals the main problems exposed in the southern area 500 kV main power grid. The problems include: long distance large capacity transmission line proportion, the power supply development is not harmonious with the power grid development, and the 500kV transmission line corridor selection problem, etc. Some solutions and recommendations in power supply development and power grid development are given out according to the problems in the end.