The aim of this paper is to identify the quality factors of Business to Business (B2B) electronic commerce applications. Having in mind the above-mentioned goal, a model will be developed in three phases. At the first stage, well-known software quality models are studied for choosing a model as the basis and using the quality factors of web applications and through referring to the quality characteristics of the existing B2B applications, the quality characteristics of B2B applications are added to the model. In the second phase, each of quality factors of model is weighted from the both viewpoints of the developer and the user. Finally, proposed model is evaluated through metric evaluation method.