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Marine evaporitic sulfates (gypsum and anhydrite) can record ancient seawater sulfur isotopic data; however, these records are scarce and widely dispersed owing to both restricted environments in which they form and their propensity to be eroded. The late Neoproterozoic–early Cambrian transition was a pivotal timeframe in Earth's history, witnessing the early evolution of animal life and major environmental changes. Seawater chemistry changed abruptly during this interval, including significant changes to the sulfur cycle as evidenced by unusually high sulfur isotopic values. This positive sulfur excursion, termed the Yudomski Event, has been reported previously from early and middle Cambrian units in Siberia, Iran, Australia, and India. In this study, we provide the first report of the Yudomski Event in early and middle Cambrian evaporites from the Tarim Basin, northwestern China. Our data support this event having been of global significance. We additionally report early and middle Ordovician sulfur data from China, which constrain the decline of the Yudomski Event to the late Cambrian. [ABSTRACT FROM AUTHOR]