Abstract: The magma mingling between mafic magma and felsic magma is the primary mechanism responsible for the granitoids of crust-mantle mixed source. The dark colored, microgranular and igneous-texture enclaves provide reliable evidence that indicates the existence of magma mingling. These enclaves have the following characteristics: (1) the form of enclaves usually presents an equi-axed shape, which shows that enclave magma existed in the host magma with a globule liquid state; (2) since the temperature of basic magma is higher than acidic magma (temperature excess about 300℃), this type of enclaves often has quenched margin; (3) the enclaves sometimes contain back veins; (4) feldspar xenocrysts captured from the host magma can be seen in the enclaves. Three typical granitic complexes (Pingtan, Putuoshan, Huashan-Guposhan) containing dark colored microgranular enclaves are exemplified in this paper. The formation of dark colored microgranular enclaves can be explained by the injection of the basaltic magma from deep seated magma chamber toward hypabyssal acidic magma champer.