Abstract: When the formation pressure of carbonate condensate gas reservoir drops below the dew point pressure,the condensate oil will be precipitated in formation and the wellbore,and then there will be the difference between the oil and gas production at the wellhead and downhole,which brings the difficulty for reserve calculation.Through empirical formula fitting,the dew point pressure can be obtained.When the formation pressure is greater than the dew point pressure,the wellhead oil will be folded into the gas,and the condensate gas reserve can be obtained by single-phase gas.Through oil-gas ratio,the condensate oil and dry gas reserves can be calculated.When the formation pressure is less than the dew point pressure,multiple flows will occur in the formation and then the dry gas and condensate oil reserves can be separately calculated.Through application results comparison,the calculation results with this method is accurate and reliable.