As a result of deregulation, distributed generation(DG) systems with distributed generators installed in the middleor low voltage networks become popular in distribution systems.Traditional protections developed in radial systems are difficult incoordination and in protecting against high impedance fault(HIF), sometimes it may cause nuisance tripping in the DGsystems. A decentralized multi-agent based protection withcapability of HIF detection, fault location and load shedding forthe DG systems is proposed in the paper. Digital relay is designedas a relay agent which is capable of searching for informationfrom other relay agents, interacting with other relay agents andperforming tasks of protection with autonomy and cooperating.The agent based protection scheme is also presented. EMTPsimulation results show that the proposed agent based protectionscheme can remove the influence of load switching operations,protect against HIF, electric shock. The prototype of relay agentis developed, the research is now in progress on testing theprototype in dynamic power system.