More and more therapeutic monoclonal antibodies(mAbs)are widely used for treating various illnesses such as cancer and autoimmune diseases due to the specific and efficient properties of mAbs.All of the currently licensed therapeutic mAbs are of the IgG class.Fc region of IgG has a N-glycan which is structural heterogeneity.The glycan on Fc region has many significant roles on the structure,the effector functions and pharmacokinetics of mAbs.The glycan of Fc region can be changed through genome editing and optimization of cell culture condition.This review presents an overview of the role of the various glycans in the effector functions of therapeutic mAbs and the impact of various parameters on glycosylation pattern of therapeutic mAbs.