In this study the influence of the concentration level of cetyl trimethyl ammonium bromide (CTAB) as the ablation environmental medium on the characteristics of graphene oxide nanosheets, produced by laser ablation method has been surveyed. The second harmonic of a Q-switched Nd:YAG laser at 532 nm wavelength and 7 ns pulse width and 0.5 J/cm(2) fluence was used to irradiate a graphite plate in CTAB solution. The produced samples were characterized by field emission scanning electron microscopy (FE-SEM), UV-Vis-NIR absorption spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman and photoluminescence (PL) spectroscopy. Raman results exhibit that the 0.04 M concentration of CTAB is the optimum concentration for producing high-quality graphene oxide nanosheets. The experimental results suggest that the amount of defects and the number of graphene oxide layers can be changed with adjusting the concentration level of CTAB in suspensions. This paper can be beneficial guidance to produce of high-quality graphene oxide nanosheets. (C) 2017 Elsevier B.V. All rights reserved.