On the basis of the series of annual maximum wind velocity at 86 natio nal weather stations in Guangdong Province from 1951 to 2003, the return periods of annual maximum wind velocity of every station are calculated with the functi on of extremeI using three methods of estimation of parameters, i.e., squares method, Gumbel's method and the method of maximum likelihood. The fitting result s show that Gumbel's method is the best in most cases, even in the case that the squares method or the method of maximum likelihood seems better and its choicene ss index is closer to that of the best method.