Abstract: The fractured gas condensate reservoir is very complicated gas reservoir，its material balance equation differs from that for conventional gas reservoir greatly.Based on the principle of material balance，the new material balance equation for fractured gas condensate reservoir is established by considering dual-porosity system，as well as the difference of the compressibility between rock block system and fracutre system and irreducible water saturation，the diagnostic plot from the equation can be used for calculate the gas condensate geologic reserve of fracture system and rock block system.By means of establishment of the concept model of single well numerical simulation，the pressure and deliverability data are calculated by using the model，the comparision of the gas condensate reserve of fracture and rock block systems calculated with the method and the practical reserve proves the correction of the method.The practical production data from a certain fractured gas condensate reservoir is used for calculation by applying the new material balance method，result indicates the method can be used for calculating the fractures of fractured gas condensate reservoir and the gas condensate reserve of rock block system accurately.

Key words: fractured reservoir, material balance equation, gas condensate reservoir, diagnostic plot, reserve