Abstract: Four U-Pb zircon ages ranging 123～130Ma for the Zhujiapu, Jiaoyan gabbro and Xiaohekou pyroxenite-gabbro intrusions in the Dabie Mountains suggest that these mafic-ultramafic intrusio11s are of the post-collisional origin and crystallized in the Cretaceous．In view of that the Cretaceous granitic dykes cut across the mafic-ultramafic intrusions, the large scale Cretaceous magmatic event in the Dabie Mountains was initiated by partial melting of the mantle in depth, which may be caused by upwelling of the mantle beneath the Dahie Mountains at that time．