In the Web services environment, Service Level Agreements (SLA) refer to mutually agreed understandings and expectations of service provision between service consumers and providers. Although management of SLA is critical to wide adoption of Web services technologies in the real world, support for it is very limited nowadays. There lacks adequate frameworks and technologies supporting various SLA operations. This paper presents an agent-based framework which utilises the agents' ability of negotiation, interaction, and cooperation to facilitate autonomous and flexible SLA management. Based on this framework, mechanisms for autonomous SLA formation, recovery, and profiling are proposed and discussed.