The adsorption of formaldehyde (H2CO) on the Fe site of clean and M2+ (Ca2+, Sr2+ and Ba2+) doped LaFeO3 (0 1 0) surface have been investigated using the density functional theory (DFT) method. Calculation results show that the oxygen atom of the H2CO molecule prefers to be adsorbed on the Fe site of the clean LaFeO3 (0 1 0) surface. The adsorption of H2CO could change the electronic properties of the LaFeO3, indicating that the LaFeO3 could be used as gas sensing material to detect the H2CO gas. The analysis results of the DOS suggest that the bonding mechanism between the H2CO molecule and the Fe site is mainly from the interaction between the Fe 3d and H2CO 2p orbital. Comparing with the binding energy and the net charge-transfer, we find that the M2+ (Ca2+, Sr2+ and Ba2+) doping cannot improve the sensitivity of the LaFeO3 to the H2CO gas. (C) 2011 Elsevier B.V. All rights reserved.