Land resources carrying capacity security is a very important issue which has a significant influence on the social stability of both a country and a region.Meanwhile,the fluctuation of grain output has a close relation with land resources carrying capacity security.Thereby,the researches on the periods,amplitudes and characteristics of the fluctuation of grain output and its causes are propitious to reduce the intensity of the fluctuation,to eliminate unfavorable factors,and further to keep the stability of grain output to insure land resources carrying capacity security.Empirical Mode Decomposition(EMD) is a powerful method for analyzing the nonlinear and non-stationary time series.Therefore EMD method was introduced to study the fluctuation of grain production in Shandong Province,and the data have been decomposed into two imfs and a residual trend term.The conclusions are drawn: The fluctuations of grain output have 3.5-year,7.5-year,10-year and 20-year time scales.Shown from the residual trend term,the grain output has increased continually since 1949.By using dynamics modeling method,grain yields in future 20 years were simulated.Looking from the grain yield that the Shandong Province grain productivity assumes the trend of escalation and according to the existing farming inventory and the historical trend of development that there is not the grain short problem in Shandong Province.But we cannot depend upon the expansion of sown area to increase the grain yield,to guard against the initiation ecological questions.