Abstract: The No.3 intrusion in Xingdi area belongs to the Xingdi River basic-ultrabasic complex belt on the south of Xingdi fault zone, of which secondary faults control the No.3 intrusion. It has abundant lithofacies zonation(gabbro facies and olivine-pyroxenite facies), and the alternations are in the olivine-pyroxenite facies. The rocks belong to tholeiite basalt with features of low total rare earth, obvious fractionation of REE and weak Eu anomaly. The m/f ratio is greater than 2, which is conducive to the formation of Cu-Ni deposit. With the U-Pb isotope age of 716.7±2.4 Ma, the gabbro selected from the No.3 intrusion is formed in an intracontinental rift, which is something to do with Rodina supercontinent breakup event. Through comparison with No.2 intrusion, where a small copper nickel ore was explored, similar features of petrography, petrology, REE distribution pattern, physic-chemical characteristics and alternation features were identified, in addition, the two intrusions were both formed in Neoproterozoic Era. So, the No.3 intrusion has fairly good prospecting potential.