For Chemical Vapor Deposition (CVD) grown graphene on Cu substrate, deviation from atomic orientation in crystals may be resulted from diffusion of abnormalities in the form of Cu nanoparticle (NP) formation or defects and affects graphene quality and properties drastically. However, for the uniform graphene deposition, mechanism of nanoparticle formation and its suppression procedure need to be better understood. We report growth of graphene, affected by Cu nanoparticles (NPs) emergence on Cu substrates. In the current study, growth of these nanoparticles has been suppressed by fine tuning of carrier gas by two-fold gas insertion mechanism and hence, quality and uniformity of graphene is significantly improved. It has been also observed that during the deposition by CVD, Cu nanoparticles cluster preferentially on wrinkles or terrace of the Cu surface. Composition of NP is extensively studied and found to be the oxide nanoparticle of Cu. Our result, controlled NP growth affecting deposition of graphene layer would provide useful insight on the growth of uniform and high quality Single layer or bilayer graphene for numerous electronics applications. (C) 2016 Elsevier B.V. All rights reserved.