Based on the simplification equivalent network， for the distribution system with distributed generations， a new reliability evaluation method by the Monte Carlo time sequential simulation is presented. After the zone element failure effect table is obtained on the simplification network， the impact of the DGs' stochastic power output， statuses of the devices， and the stochastic capacity of the loads on the distribution system are analyzed and calculated by the Monte Carlo time sequential simulation. By the equivalent network， the ransack processing during the reliability analysis and calculation is reduced significantly， and the repetitive failure analysis is avoided by the method of zone element failure effect table. As a result， the simulation calculation procedure is accelerated. Furthermore， during the stochastic simulation processing， the strategy of synchronous sampling for the statuses of DGs and the network devices is employed. Compared with the traditional methods， the proposed method increases the precision of the simulation and the speed of calculation. The results of the test examples demonstrate the validity and practicability of the new method.