In a first principles study of the formaldehyde adsorption on ZnO surface, we found a novel chain adsorption structure on ZnO (10 (1) over bar0) plane. This adsorption structure results from the electrostatic interactions between those adsorbed formaldehyde molecules and the unique arrangement of Zn-O surface dimers on (10 (1) over bar0) plane. This adsorption mechanism has the potential to extend to other wurtzite materials' (10 (1) over bar0) plane and other similar cases. As the physical adsorption configurations are unstable, the chemical adsorption has to happen. The electronic properties show that the C = O double bond in CH2O turns into C-O single bond and the highest occupied molecule orbital (HOMO) of formaldehyde is lifted into ZnO band gap becoming the hole trapping center. These results may be meaningful for formaldehyde degradation and detection. (C) 2017 Elsevier B.V. All rights reserved.