Based on first-principles calculations, the properties of nitrobenzene adsorption on graphene have been investigated. The results show that nitrobenzene prefers to be parallel to the plane of graphene with nitro closer to graphene than phenyl. Due to molecular adsorption, there is a doping band near Fermi energy. The adsorbed molecules will become perpendicular to the plane of graphene under a electrostatic field, and the doping band varies conspicuously with respect to Fermi energy. In addition, a 5000 steps MD is performed at T=300 K to test the stability of nitrobenzene molecules adsorbed erectly on graphene under electric field. (C) 2014 Elsevier B.V. All rights reserved.