There exist a number of diabase rock bodies in Wuding area, Yunnan Province, and the geochemistry and La-ICP-MS U-Pb age for zircons in Haizi diabase are reported in this paper. The U-Pb age of 1767±15 Ma(MSWD=0.19，n=17) reflected that the widely spread diabases in Wuding area intruded in the late Paleoproterozoic. The petrochemistry of Haizi diabase characterized by low SiO2, MgO and high TiO2(3.24%～4.02%), alkaline(K2O+Na2O) and P2O5(0.32%～0.45%) content, which has the petrochemical characteristics of the tholeiitic basalt. The large ion lithophile elements(LILE) are enriched and the high field strength elements(HFSE) express without obviously anomaly for Haizi diabase, and the other geochemical parameters are also similar to the characteristics of Hawaii alkaline island basalt. The MORB normalized trace elements and chondrite normalized REE patterns of Haizi diabase are highly in accordance with the tipical OIB and high-Ti basalt in Emeishan. The resource area of primitive magma for Haizi diabase which derived from the patial melting of relatively enriched transitional mantle is spinel-bearing peridotite. A little lower crustal material was contaminated during the primitive magma evolution. The Haizi diabse and the other paleoproterozoic magmatic rocks which widely spread in the southwest of Yangtze block, formed in the tectonic background of the global Columbia supercontinent breakup. The typical OIB characteristics for Haizi diabase provides the most important geochemical evidence for mantle plume activity which result in the breakup of Columbia supercontinent.