An agent-based system is a complex software system with functional and nonfunctional constrain. Designing and building such system is a complex task. This article presents a goal-driven use case based method for agent-based system requirements analysis. The use case approach is used to elicit system requirements from user?s point of view. Related use cases are assigned to corresponding roles. Each use case is then extended with goals for implicit requirements analysis from a role?s point of view. Each role is treated as internal actor to find more system specific use cases. Five relationships between use cases and goals are then identified: satisfied, satisfiable, denied, deniable, and independent. Those relationships help find the relationship among roles. Such relationships can be classified as cooperative, conflict, counterbalanced, and irrelevant. Identifying those relationships assists the system analyzer to analyze and optimized the relationships among roles. The contribution of this article is a proposal to a systematic approach for implicit requirements analysis for agent-based systems.