Abstract: Tazhong?1gas field is a condensate gas reservoir with fractured?vuggy carbonate rocks. Production test indicated that the deplete development process just obtained the condensate oil recovery of about25%. As a result of poor interwell connectivity, conventional gas injection to maintain pressure process was difficult to use. This paper makes a comparison of retrograde condensation mechanism of fractured?vuggy carbonate condensate gas reservoir with that of sandstone condensate gas reservoir. On the basis of laboratory and field test researches, it demonstrates the feasibility of deplete followed by water injection process applied to the fractured?vuggy carbonate condensate gas reservoir. The result shows that the storage space and flow path in such a condensate gas reservoir are mainly fractures and cavities, and gravitational differentiation allows the retrograded liquid to concentrate at the bottom of fracture?vug unit, so single well water injection approach can be used to displace the condensate oil formed by retrograde condensation in these fractures and cavities, and to greatly enhance the condensate oil recovery with simplicity and effectivity