Graphene has attracted immense investigation since its discovery. Lattice imperfections are introduced into graphene unavoidably during graphene growth or processing. These structural defects are known to significantly affect electronic and chemical properties of graphene. A comprehensive understanding of graphene defect is thus of critical importance. Here we review the major progresses made in defect-related engineering of graphene. Firstly, we give a brief introduction on the types of defects in graphene. Secondly, the generation and healing of the graphene defects are summarized. Then, the effects of defects on the chemical, electronic, magnetic, and mechanical properties of graphene are discussed. Finally, we address the associated challenges and prospects on the future study of defects in graphene and other nanocarbon materials. Copyright (C) 2015, The editorial office of Journal of Materials Science & Technology. Published by Elsevier Limited. All rights reserved.