In the current study,phylogeographic structure of Spiraea mongolica (Rosaceae) was investigated based on cpDNA markers (trnL-trnF and rps15-ycf1).Three hundreds and twenty four individuals distributed in 23 natural populations were used in the study covering the QTP and adjacent highlands.The result showed that:(1)The closely related haplotypes in this study tending to occur in same population indicated significantly phylogeographic pattern within the entire distribution range.(2)About 71.4% of the 35 haplotypes detected from all individuals were endemic in certain population;phylogenetic analysis divided all the haplotypes into three highly supported dades,in which H1 was the more ancient and highly distributed haploptype.(3)Mismatch distribution analysis indicated the species had experienced demographic expansion up to some extent since long time,but the expansion was not so rapid.(4)The results of BEAST analysis revealed that cladistics differentiation of S.mongolica occurred about 45 Mya.This research suggested that there are no less than three glacial refugia of S.mongolica in the QTP and adjacent highlands.The distribution of S.mongolica on the QTP and adjacent highlands was due to the combine effects of climatic instability during quaternary glacial-interglacial episodes and the uplifting of QTP.