It is necessary to evaluate the reliability of the power system, for the safe and stable operation of the power system. The influence of the inserted wind farms and PV farms on the reliability of the power system is studied. Reliability models of renewable-based units are developed. In these models, both component failure rates and uncertainty nature of renewable resources are taken into account. The multi-state models of the wind farms and PV farms is proposed. Using the fuzzy C-means clustering algorithm to analyze the state models. Using state enumeration method and conditional probability to build the the probabilistic model of the power system. The reliability evaluation of RBTS and IEEE-RTS with wind and solar generation is implemented. And different reliability indices are calculated. The obtained results well confirms the proposed method simplicity and accuracy.