Mesozoic A-type granites with a slightly low-δ18O signature are widely distributed in active continental margin of E.China. Among them the previous geochemical evidence of Nianzishan pluton argues for presence of recycling of altered juvenile crust by subduction. Our in-situ SIMS O-Li isotopes of zircon provide new insights on the petrogenesis and evolution of the Nianzishan granite. Low-U magmatic zircons from five samples are characterized by slightly low δ18O (4.6 - 4.9‰) that are positively correlated with crystallization temperature. Another sample yields low δ18O value of ~4.0‰, which is likely achieved by assimilation of low-δ18O wall-rock during granite emplacement. In-situ Li-isotope analysis of large and euhedral zircons shows a weighted average δ7Li of 0.7 ± 1.7‰.