The present paper has calculated out the chaotic characteristic quantities of the 500hPa day-to-day geopotential height time series of eleven representative observation sta-tions in East Asia in 1979～1988.Results show that the corresponding incidence dimensional-ity is fractional,positive,zero and negfltive valties all exist in the complete Lyapunov expo-nential spectrum, with the sum of the Lyapunov exponents(Σλ_k)less than zero. Therefore.on the whole,the weather attractor in relation to East Asia is supported by a limited space. The system mean K entropy displayed by the weather attractors of East Asia is about0.1008.Thus,the predictable period is about 9. 92 days. Generally speaking,the predictable period in the northern part of the area is a bit longer.