The energy performance of two structures of naturally ventilated double-skin façades (DSF) with Venetian blinds is evaluated in the Yangtze River Area (YRA) by using an improved zonal model, which is validated by measured data. The results show that the thermal performance of the naturally ventilated DSF with interior double glass is better than that of the naturally ventilated DSF with exterior double glass. The heat gains/losses of several of the most commonly used fabrics in six representative cities in the YRA are simulated and compared. In the cooling season, the heat gain of the DSF (Case F) is 11.00 %–43.16 % smaller than that of the most commonly used fabric (Case A). The heat gain through the DSF is 1.70 %–30.32 % smaller than those for the thermally well-insulated fabrics (Cases B–D) in the east and west orientations. Compared with the double-glazing façade (Case E), the average heat gain of the DSF is 45.5 % smaller. In the heating season, the heat loss through the DSF is reduced by 14 % and 72 % compared with Cases A and E, respectively. From the perspective of energy demand for cooling and heating, the DSF has good applicability in the YRA in China.