The magmatic Cu-Ni sulfide deposit is mainly hosted in mafic-ultramafic intrusions which are generally small scales. The ore body is mainly hosted in the base of the intrusion. This forms a large number of deposits which we call “mall intrusion forming large deposit”. In the world，there are many mafic-ultramafic intrusions，but how to determine the metallogenic potential of intrusion has been concerned all the time. In this paper，based on previous studies，we take eastern Tianshan as an example，compare and analyze the geological and geochemical characteristics of the economic mineralized mafic-ultramafic intrusions and the uneconomic mineralized mafic-ultramafic intrusions，in order to distinguish the metallogenic potential from theory. The prospecting evaluation indexes are gained from this study，mineralized mafic-ultramafic intrusions are generally characteristic by right incline in Chondrite normalized REE pattern diagrams；several stages of magma intruding are important；a certain amount of orthopyroxene is contained in the rock；the mineral grains are obviously different， et al.