The nanocrystalline powders Nd1-xCaxFeO3 prepared by sol-gel method crystallized as perovskite orthorhombic structure. The mean grain size of Nd1-xCaxFeO3 powders were about 15~ 40 nm. The conductivity of the Ca doped samples was enhanced, compared to that of the undoped. The Nd0.9Ca0.1FeO3-based sensor showed good gas sensing properties to ethanol and acetone. The responses of the Nd0.9Ca0.1FeO3-based sensor to 600ppm ethanol and acetone were about 158.4 at 220°C and 61.7 at 240°C, respectively.