Basic-ultrabasic rocks are developed in Taihang Mountain area. With olivine pyroxene hornblendite from the Yaogou hornblendite body in the Wang'anzhen batholith of north Taihang Mountains as the study object, the authors carried out a preliminary study of the mineralogical characteristics and formation conditions of the amphiboles so as to investigate their genetic significance. The results show that there are two kinds of amphiboles in the olivine pyroxene hornblendite, which belong to calcic amphibole with (Ca+Na)_B≥1.00 and Na_B<0.50. Their Si/(Si+Ti+A1) ratios are between 0.704 2 and 0.788 5, indicating that they are mantle amphiboles. Based on the relative content of Na, K, Ti, Al and Fe³⁺, the authors further divided the calcic amphibole into magnesium hastingsite in brown color and magnesium hastingsitic hornblende to edenitic hornblende in green color. The amphibole zonation indicates that the amphiboles were formed at different stages of the same magma crystallization characterized by different pressure and temperature conditions. The magnesium hastingsite was crystallized at high temperature and pressure and in great depth, belonging to the lower crustal environment. The edge of the amphibole was generated in a lower pressure crustal environment. The amphibole magma was derived from the upper mantle and began to concentrate before the Yanshanian movement in late Triassic. Later, intermediate-acid magma was emplaced to form a granitic batholith. These data indicate that partial melting in the lithosphere of the North China Craton took place in late Triassic and that the North China Craton started to be destroyed at that time.