Ni-LaFeO3 powder was prepared by the method of microwave chemical synthesis.The crystal structure and morphologies of Ni-LaFeO3 were characterized.The results show that the Ni-LaFeO3 was pure perovskite structure,the dispersive of Ni-LaFeO3 particle is uniform and the particle size was about 187nm.The sensitivity and selectivity of LaFe0.9Ni0.1O3 for 5.0×10-4 formaldehyde are good,the response and recovery time are about 20 and 30s,respectively.