In order to explore the origin of hypabyssal and ultrahypabyssal neutral- acidic complex which had been related closely with porphyry tungsten anct molybdenum deposit in the region of Yangchuling, the experiment was engaged in melting quartz-diorite, granodiorite and granodiorite-porphyry, Which are the' main types of the rocks in that region. The results of experiment indicate that the primary melting temperature of quartz-diorite is higher than 800℃， those of granodiorite and granodiorite-porphyry are 780℃，when the pressure is at 2kb. They are higher than the primary meltiaxg temperature of similar rocks with plutonic origin at home and abroad, and much higher than that of gran- ite with granitization or migmatization. In this paper, the authors have discus- sed some factors, particularly the pressure and water, which have a great influences with the primary melting temperature of rocks. In combination with other geological features; the authors consider that the complex in the region of Yangchuling is of origin of crust-mantle type with platonic contamination.