Abstract：In this study, the hierarchical clustering method is adopted to classify GPS horizontal velocity field of the Sichuan-Yunnan region, then the F statistic test is employed to correct the misclassification of the GPS site in the geographical space. On this basis, taking account of the DB index and the irreversibility of the hierarchical clustering, the former classification is re-clustered. Finally, the Sichuan-Yunnan region is ultimately divided into six blocks: Tibet block (BYw), Aba block (BYe), Sichuan-Yunnan rhombic block (CD), south China block (SC), Tengchong-Baoshan block (DSw) and Indosinian block (DSe). Among them, the west and north boundaries of the CD block are the three-river fault area of “three-river parallel flow” and a velocity step line in the Batang region, respectively. Moreover, main Bayan Har fault divides the Bayan Har block (BY) into two blocks: BYw and BYe. The block division model of the Sichuan-Yunnan region is a reasonable scheme in mathematical sense, which is basically consistent with the results from geological data, can provide an explanation in another dimension for the division of the Sichuan-Yunnan region.
