Abstract: Web usage mining is a tool for web personalization, since it captures and models behaviors and profiles of users interacting with a web site. These models can be used by personalization systems to better understand the behavioral characteristics of visitors improve the organization, the content and the structure of web sites and provide dynamic recommendations to visitors. This paper describes the design of a web usage mining architecture for web personalization (PWUM) implemented using a multi-agent platform. It first gives an overview of related work in personalization and web usage mining domains and then introduces the PWUM architecture. This latter is composed of a set of autonomous agents interacting together in order to fulfill the main goal of the system. Agents are divided into modules that have well- defined tasks and that are further divided into two working groups: offline and online. The data mining module is the main module of the architecture since it provides the personalization module with patterns, the crucial key of the whole system. The multi-agent system in PWUM has been implemented using the Jade idiom.