Modeling of some parameters of wet ball milling system of copper sulphide ore was performed in this study. A three level Box-Bhenken design combining a response surface methodology (RSM) with quadratic model was employed for modeling of key operating parameters of ball mills. Grinding experiments were designed and executed by a laboratory ball mill, considering ball size, ball charge and solid content as variables. Grinding tests were performed changing these three variables (ball size, ball charge and solid content) in the range of 20-40. mm, 20-40% and 65-80% respectively. Product 80% passing size (d80) was defined as process response. A quadratic model was developed to demonstrate the effect of each parameter and its interaction with d80 of product. Predicted values of response obtained using model equation were in good agreement with the experimental values (R-2 value of 0.994 for d80). Finer d80 was achieved using greater ball charges with smaller ball sizes. More favorable results were also obtained at the center of solid content level. Results suggest that RSM could be efficiently applied for modeling of ball milling system of some copper sulphide ores. (C) 2013 Elsevier B.V. All rights reserved.