Manufacture cost and service life of WTGS (wind turbine generator system)are dependent on fatigue load during operation,extreme load and designing standard. Nowadays, most designing standard adopted in China is made on the basis of external condition similar to Europe. When those standards are used for designing WTGS in typhoon area without consideration, project risk or manufacturing cost will rise. Typhoon-resistant WTGS with reasonable cost could not be designed and produced unless understanding meteorological characters of typhoon and its destroying mechanism.