Preference Elicitation is very important for online shopping interactive applications. The potential buyers usually have interest in some of the attributes of the product they want to purchase. While the current online shopping systems allow the users to provide some keywords and other information in order to ?lter and get only what they need, these latter feel that what they get does not necessarily meet their satisfaction. In this paper, we propose a new shopping system that enables the customers to express their needs when buying a product online. More precisely, the users are given the ability to provide their requirements and desires in a friendly and interactive way. The system will then provide a list of suggestions meeting the users’ requirements and maximizing their desires. Requirements and desires are managed, in a unique model, respectively as a set of hard constraints and preferences where these latter can be quantitative (numerical), qualitative (ordinal) or both. These constraints and preferences represent a constraint optimization problem where optimal solutions (best outcomes) are those satisfying the hard constraints and maximizing the user’s preferences. The branch and bound method is applied in order to provide the user with a list of best outcomes.