Zircons separated from an orthogneiss sample of the Po Sen Complex were dated to determine the protolith age for the complex. Twelve SHRIMP U-Pb zircon analyses give concordant ages concentrated at 751± 7 Ma (weighted mean), and one inherited zircon core gives age of 1809± 21 Ma. TIMS U-Pb zircon dating of the complex yields 760± 25 Ma, consistent with SHRIMP U-Pb dates. These results indicate the protolith of the Po Sen Complex (primary magma crystallization age) to be Neoproterozoic (ca. 750 Ma).