Abstract:The leucocratic constituents in serpentinite of Jinshajiang ophilite belt are called leucocratic rocks, which , assuming the massive from, are wrapped in serpentinite. Composed mainly of anorthosite and plagiogranite, the leucocratic rocks show distinct Eu positive anomaly.The REE parametric diagram and variations of Nb/Ta and Zr/Hf values suggest crystallization segregation, characterized by enrichment of incompatible elements such as Sr, Ba, Nb, Ta, Zr and Hf and depletion of Compatible elemelnts like Sr, V, Co and Ni. All of these characteristics are in contrast with their host rock_serpentinite and show that the leucocratic rocks were produced by crystallization differentiation of ultramafic magma.