La1-xPbxFeO3 (x=0.0-0.5) ceramic powders with orthogonal perovskite structure were prepared using sol-gel method. With the increasing Pb content x, the conductivity for La1-xPbxFeO3 increases to a maximum value at x=0.2, then falls off to minimum value at x = 0.2, and finally increases again. Among ceramics La1-xPbxFeO3 (x <= 0.5), the sample La0.68Pb0.32FeO3 with x = 0.32 shows the best sensitivity to acetone gas. La0.68Pb0.32FeO3 ceramics with high sensitivity, low operating temperature to acetone gas, excellent stability in air and short response and recovery times can be used as a new type of gas-sensing material for detecting acetone gas. (c) 2005 Elsevier B.V. All rights reserved.