The acetone-sensing properties of the undoped and Pd doped perovskite-type oxides NdFeO₃ were investigated from room temperature to 400℃. The perovskite-type NdFeO₃ was synthesized by a sol-gel method, and the dopants Pd with the content from 1wt% to 5wt% were implanted into NdFeO₃ nanoparticles by thermal diffusion. X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques show that NdFeO₃ is an orthorhombic structure with the average particle size of about 40 nm. A giant acetone-sensing response of 675.7 is observed when the Pd content in NdFeO₃ powders is about 3wt%. The response and recovery time of the sensor to the 5×10^-4 acetone gas are 16 and 1 s, respectively. At the same time, it performs a good selectivity to acetone gas and may be a new promising material candidate for the acetone-sensor development.