It is discovered that the Wangjiangshan gabbro from the Hannan intrusive complex in the Xixiang County, Shaanxi Province contains abundant zircons; 7 g zircons, well-crystallized, simple in internal structure and origin, homogenious in U-Pb age and Hf isotopic composition, and with crystal size of 0.2 to 0.3 mm have been separated from 600 kg gabbro sample. U-Pb dating was carried out for the zircons using three different methods in three different laboratories; consistent ages were obtained: 819.8 ± 2.5 Ma (LA-ICP-MS), 821.7 ± 1.7 Ma (LA-MC-ICPMS) and 822.1 ± 4.5 Ma (SHRIMP). The Hf isotopic compositions of the zircons were measured in four authoritative laboratories and consistent 176Hf/177Hf ratios were obtained, the weighted average 176Hf/177Hf ratio of the total 421 analyses is 0.282535 ± 0.000003 (2σ). The sampled gabbro is well-outcropped, fresh, with large scale in smapling site, and convenient to access. Hence the zircons separated from the Wangjiangshan gabbro seem to meet the main requirements of Hf analysis standard; might serve as a standard zircon for Hf analysis. Hf isotopic standard preparation is to get accurate and reliable determination of Hf isotopic data ,and has very important practical value and scientific significance.