Experiment design-response surface methodology (RSM) is used to model and to optimize the activation of methane (C 1) using ethane (Q) as co-reactant into higher hydrocarbons, over Zn-containing zeolite catalyst. The application of this methodology allows a better understanding of the influence of the different factors: time on stream (TOS), space velocity of C2 (GHSV-C2), molar fraction of C1/(C1 + C2) (XCl) and reaction temperature, on the C I conversion, reducing the operation costs, achieving efficiency and effectiveness of this process. Box-Behnken design was development with different levels of the factors, determining its influence on the C I conversion in order to obtain responses surfaces. In this way, we found the best combination in the reaction parameters that allowed us to optimize the process. The results indicated that the reaction time, the XCl and the interactions of the TOS-temperature factors, have the main influence on Cl conversion, in agreement with the experimental results reported previously. (C) 2007 Elsevier B.V. All rights reserved.