Abstract:Based on the ground meteorological indicators,the climate indexes and the NOAA reanalysis data during 1960—2012,spring-drought-period(April—May) monthly precipitation amounts in Jilin Province are analyzed by using power spectrum analysis,time-scale decomposition,cross-examination stepwise regression analysis,etc.This paper aims to find proper potential annual influence factors and decadal ones.The results show that April—May precipitation in Jilin Province has two significant periods,namely,2—4 years and about 10 years.In terms of the decadal scale,precipitation in April is closely related to the Southern Hemisphere Annular Mode Index in March and the 850 hPa meridional wind in March over the high-latitude area in East Russia,while that in May is related to the Northern Hemisphere Annular Mode Index in May and the Pacific mid-high-latitude circulations in April.As for the interannual scale,precipitation in April has close relationship with the Multivariate ENSO Index in March,the local relative humidity in April and the 850 hPa meridional wind in April over coastal areas in East and North China,while that in May does with the contemporary North Atlantic Oscillation Index,the local relative humidity and the surface pressure.The coefficients of correlation between the real values and the fitted ones are 0.67(April) and 0.81(May) separately,and proper potential influence factors play more important roles than the model structure.