The study area is located in the south of late Paleozoic to early Mesozoic rift zone in Zongwulong Mountain—Qinghai Nanshan, and its tectonic position lies in the third grade tectonic unit of Oulongbuluke Block in Qinling—Qilian—Kunlun orogenic belts. The rocks in this district consist of mainly acid rocks and much less mafic rocks. Up to now, little study on petrology and geochemistry of mafic rocks in Shidiquan district in Delingha city has been reported, and the formation age of mafic rocks is still unknown as well. Therefore, the author of this paper intends to take mafic rocks that crop out in Shidiquan district as research objects. Through detailed field observation as well as petrology analysis, geochemistry analysis and U Pb isotopic dating method, we will discuss the problems of petrology, geochemical characteristics, formation time and magma origin in the study area in depth.Methods: A gabbro sample, which weighs about 40~55kg, was collected in Shidiquan area for isotopic dating, with its geographical coordinate of E96°09′25″, N37°30′40″. Zircon separation was carried out using conventional methods, and zircon grains were then hand picked under a binocular microscope. Afterwards, zircon grains with fine crystalline shape and transparency were mounted in epoxy mounts and next been polished to section the crystals in half for further analysis. These steps were undertaken at the Langfang Rock and mineral testing technology, Co. Ltd, Hebei province, China. Later, Then zircon grains were taken cathodoluminescence (CL) images by using scanning electron microscope to reveal their internal structures. Zircon U–Pb isotopic ages were analyzed using the laser ablation multicollector inductively coupled plasma mass spectrometry (LA MC ICP MS) at the at the State Key Laboratory of Continental Dynamics, Northwest University, China. Analytical instruments include Agilent7500a type four stage rod mass spectrometer, Geolas200M laser ablation system and excimer laser with wavelength of 193nm. The diameter of laser beam was 30 μm and the depth of it is 20~40 μm. and using He as acarrier gas.Zircon age is calculated using standard zircon 91500 as an external standard, the element content of the United States by the national standard material board synthetic silicate glass NIST610 as external standard, SiO2 content for internal standard calibration. Zircon content and isotopic data by China University of Geosciences Liu Yongsheng bo scholar research and development of ICPMSDataCal program and Ludwig Kr Isoplot for data processing and drawing, the Tom Andersen method for correction of common lead.Results: LA ICP MS zircon U Pb dating of the gabbro shows an Paleoproterozoic age of 2467±13Ma. The analyses of major and trace elements show that the Shidiquan gabbros have characteristic of slightly rich in Mg, Al and Na.Conclusions: The Shidiquan gabbro samples belong to the aluminum basite and are derived from mantle magma.Comprehensive analyses suggest that the Shidiquan gabbro is the product of uprising melt from upper mantle during the breakup of the continental basement. This study provide the evidence that the strong magmatic activity has occurred in the paleoproterozoic in the Shidiquan area and confirmed that the age of the Dakendaban Group may extend down to the late Neoarchean.