Lhasa eclogite belt was newly discovered in the Lhasa terrane, Tibet. It is located in the north of the Gangdese island arc belt. Geochmeical characteristics, SrNd isotopic compositions and SmNd isotopic chronology of the eclogites were analysed in this study. The major element compositions and relatively high εNd (305Ma) of about +7.9 for the eclogites suggest that the protoliths of eclogites are ancient basaltic rocks developed in the ocean crust, similar to the typical NMORB, and likely derived from the depleted mantle. The (87Sr/86Sr)i of the eclogites vary over a wide range, from 0.70335~0.70457, which is not closely relevant to the εNd (305Ma) and trace elements. We favor that this irrelevance may be due to the ocean environment of these eclogites and, later the protoliths underwent alteration by sea water after its formation. The whole rock SmNd age of 305.5±50 Ma may indicate that the eologite is likely formed during Early Carboniferous to Late Permain, during which there likely existed ancient Tethys ocean and its subduction at the north margin of the Gandese.