By borrowing the construction and evolution mechanisms of the social groups, a reputation system based on groups of autonomic elements (AE) is proposed, which is called clique-based reputation system (CRS). With the combination of the clique-based reputation evaluation and reputation inspired clique evolution, CRS makes the reputation model more realistic on evaluation of the characteristic of AE behaviors and better convergent properties. Meanwhile, the node cluster results from the clique evolution make a foundation for the differential service for AE based on reputation, incentivize them to take corporative behaviors, and provide reliable services.