The Gongdanshan block in Yishui County, Shandong Province, is a gneiss-granite dome. In the center of the dome, charnockites and supercrustal rock sequences (restites) of granulite facies are exposed widely; outwards to the northern, eastern and southern margins of the dome, there occur gneisses, amphibolite and granitoids in which leucocratic felsic veins and pegmatites are common. The granulite facies supercrustal rocks contain very few or almost no fluid inclusions; in contrast, the anatectic veins contain abundant CO2-rich fluid inclusions, a small number of H2O and CO2-H2O inclusions and occassionally saline aqueous inclusions with solid(s). Microthermometry and laser Raman microprobe analyses have shown that the CO2-rich inclusions contain 70～85 mol.% CO2 with minor H2S, SO2, CH4 and H2O. The early CO2-rich inclusions have higher densities while the CO2-rich inclusions distributed along the transgranular fractures have lower densities. H2O (aqueous) inclusions belong to the products of late retrograde metamorphism after peak metamorphism. The vapor-rich inclusions of low-density are probably related to leakage or partial decrepitation of CO2 (±H2O) inclusions. The role of fluid during anatexis is tentatively discussed. It is suggested that under the pressure of the middle crust the infiltration of a CO2-H2O fluid along foliations of fissures of rocks would cause partial melting that led to the formation of garnet or orthopyroxene, with H2O entering the melt preferentially and CO2 entering the coexisting vapor garnet and/or pyroxene porphyroblasts and in quartz within felsic veins crystallized subsequently from the silication melt. The P-T conditions the rocks experienced after peak metamorphism are deduced from the mineral equilibria and the microthermometry of the fluid nclusions