Particle size analysis for samples from three last glacial cycle loesspalaeosol profiles along a northwestsoutheast transection on the Chinese Loess Plateau has been carried out. The paleoclimatic significance of grain size indices has been obtained by analyzing the fraction content variations and their comparisons with global ice volume and solar radiation variations. The results show that （i） paleoclimatic significance of the grain size indices of loesspalaeosol deposit is different with grain size fraction content and sampling points in Chinese Loess Plateau; （ii） the subcoarse grain fraction is a good proxy index of East Asia winter monsoon strength and therefore can be used to detect the global climate changes; （iii） the content of sub_fine and fine grain fractions is influenced by both the input of subcoarse grain fraction and pedogenesis; （iv） the subcoarse fraction exhibits a negative relationship with the sub_fine and fine fraction.
