How the continental crust responds geochemically to progressive extension is one of the interesting questions. The Southern Tibet Rift System (STRS) is one of the active extensional structures. The Yardoi gneiss dome, located within STRS, consists of at least four suites of Miocene granites. As crystallization ages become younger, they are characterized by decrease in Nd(t) and Sr/Y, but increase in 87Sr/86Sr(t) and Rb/Sr. Such temporal trends could be explained by sequential partial melting of first the mafic lower crustal rocks and then progressively shallower metasedimentary rocks. Together with literature data, from north to south along STRS, as the extension proceeds and the heat moves upward, sequential partial melting is common to produce Miocene magmatic rocks. The processes documented in the southern Tibet might be common in other extensional provinces and provides a new insight to unravel the mechanisms for the generation of geochemical variations in contemporaneous granites.