Abstract: For revealing the impact of regional climate variations on rice yield in East China,the time-frequency characteristics of the rice yield,average temperature and precipitation during rice growth period and the multi-time scale correlations between meteorological yield and regional climate variations in East China were analyzed by power spectrum and cross wavelet transform method.The results showed that both of rice yield fluctuate and regional climate variations in East China had the interannual and interdecadal scale periods.Positive correlation between meteorological yield and average temperature during rice growth period appeared in most of time-frequency space,higher coherence of the correlation oscillations mainly showed at 2～3 years,4～6 years,10～14 years and 16 years scale.The significant of interdecadal correlation was exhibited at a stage and the interannual correlations were localized in time space.The significant periods of the correlation oscillations between meteorological yield and precipitation during rice growth period were quasi-biannual,3～4 years,8～10 years and 16 years,the coherence of negative correlation oscillations before 1985 as a result of more precipitation was obviously higher than the positive correlation oscillations after 1985 due to less precipitation.It was found that the rice yield fluctuate had a closely relation with regional climate variations in East China,the influence of warming of regional climate on rice yield was greatly bigger than the reducing of precipitation.The main causes of rice yield fluctuate were the increasing of climatic disasters due to unusual climate changes in East China.

Key words: East China, East China, Rice yield, Climate variation, Wavelet transform