To discuss that metamorphic carbonate rocks release the amount and ability of CO
2 and CO
2 releasing conditions,CO
2 flux, which metamorphic carbonate rocks release in contact metamorphism, is analyzed and calculated quantitatively on the basis of metamorphic reaction and time integrated fluid flux. The results suggest that the value of CO
2 flux is 0.729×10
4~2.446×10
4 mol/cm
2,CO
2 is provided mainly by contact metamorphic reations. The generation and release of CO
2 are positive correlation with the degree of metamorphism, and
XCO2 in fluids continuously increases form the zone of dolomite to the zone of calcite, but in the zone of essonite, fluid flux is the largest and
XCO2 sharply decreases for the influence of magmatic water.