This thesis is based on previous studies and data of Lingtai profile in the Loess Plateau,regarding mean grain size and magnetic susceptibility as the proxy of the summer and winter monsoon.The method of Empirical Mode Decomposition(EMD)is applied,in order to separate the grain size sequence and magnetic susceptibility sequence in different cycle and investigate the evolution characteristics of east Asian paleomonsoon and its astronomical control factor during the Last 7MaB.P.The results show that the EMD m...