The strata about Permian—Triassic boundary are carbonetes continuously developed on the Great Bank of Guizhou in Southen Guizhou Province. The top of the Upper Perimian is massive bioclastic packstone, while the bottom of the Lower Triassic is calcimicrobial framestone and wackestone. 91 marine carbonete samples were sampled from the profile across the Permian—Triassic boundary, with a thickness of 81 meters. n(87Sr)/n(86Sr)ratios vary from 0.707269 to 0.707409; average value of n(87Sr)/n(86Sr)is 0.7073287, less than the average value (0.709073) of the modern seawater. The Srisotope curve of this profile indicates that the n(87Sr)/n(86Sr) ratios did not vary distinctly from the top Permian to bottom Triassic as a whole; whereas the curve waves continually in a small extent from Latest Permian to the beginning of the Triassic. The average value (0.707330) of the bottom Triassic is appreciably higher than that (0.707323) of the top Permian. The evolution trend of n(87Sr)/n(86Sr) ratios in the Great Bank of Guizhou, i.e., the Srisotope composition has not obvious change from top Permian to bottom Triassic, is different from those (remarkable rise from the Latest Permian to the beginning of the Triassic) in the Yangtze platform and other places of the world , which may be resulted from that the Great Bank of Guizhou, even though being controled by global events, has a special environmental condition, being less influenced by terrigenous matter, the crustal strontium action on Srisotope composition being very weak.