E-commerce provides several advantages for Small and Medium Enterprises (SMEs). E-commerce adoption by Indonesian SMEs is still very low. This study conducts a research to establish a maturity model of e-commerce adoption by Indonesia SMEs. It was carried out in two phases from 2014 until 2015. The result of the first phase recommends four levels of maturity model and 13 e-commerce benefits, 51 functionalities, and 9 non-functionalities that an e-commerce solution must have. The result of the second phase presents a maturity model of e-commerce adoption for SMEs in Indonesia.