In terms of the distribution system with distributed generations（DGs） especially considering the operation of micro-grids（MGs） composed of DGs and loads， a service restoration model aiming at the restoration of the most load with the least number of switching actions is built. On the basis of the proposed hierarchical control strategy among dispatching center of distribution network， MGs and DGs， this paper builds up a multi-agent system for service restoration of distribution system containing DGs and/or MGs. The proposed system applies the multi-agent theory with the satisfaction of the restriction of radial supplying， voltage， current and power capacity limits of distribution network. The proposed multi-agent service restoration system is composed of single central control agent（CAG）， several distributed generation agents（DGAGs） and micro-grid agents（MGAGs）， and many bus agents（BAGs）. The analysis of the service restoration problem of a distribution system with two substations and fourteen buses containing four DGs after occurrence of single fault and multi faults is given in the paper.