The electronic properties of NiO (1 1 0)/MAPbI(3) (1 0 0) interface are investigated by the first-principles calculations. The NiO (1 1 0)/MAPbI(3) (1 0 0) interfacial lattice mismatch is 7.3%. The binding energy of the NiO (1 1 0)/MAPbI(3) (1 0 0) interface is -0.0591/m(2), and the atoms bonding is irregular at the interface. There are some interface states nearby the NiO (1 1 0)/MAPbI(3) (1 0 0) interface. Interface states of the NiO (1 1 0)/MAPbI(3) (1 0 0) interface mainly are attributed to I-5p, O-2p and Ni-3d orbitals on the MAPbI(3) (1 0 0) layer1 and NiO (1 1 0) layer1. (C) 2018 Elsevier B.V. All rights reserved.