The Northern Xinjiang is characterized by a large number of Permian mafic-ultramafic complexes with magmatic Cu-Ni sulfide mineralization in different tectonic unit. The identification of the top and bottom of these Cu-Ni sulfide-bearing mafic-ultamafic intrusions, a worldwide problem, is significant for the blind ore exploration. According to the outcrop area and lithofacies, these complexes can be divided into large complex (>18~40 km²), small complex massif (1~5 km²) and simple rock-body (<0.1 km²). The three types differ in body size, occurrence, lithofacies, the ratio of mafic and ultramafic bodies, ore-bearing lithology, and space distribution of orebody and the ratio of Cu/Ni in orebody. The above-mentioned essential features of the complexes and mineral grain, alteration degree, basalt and diabase coeval with mafic-ultramafic intrusions, can determine the relative erosion degree of the deposits synthetically.