Reserve capacity is useful to all nodes of the grid. But different users at different nodes have different demands for power reliability. The integrated power consumption reliability model of the node is built， which takes two factors into consideration， i.e. reliability of generation and transmission system and uncertainty of load forecasting. Based on the principle that the power with high reliability has high reliability price， the influence of different reliability demand information from different users on the grid’s optimal reserve capacity is analyzed and a way to calculate different users’ reliability price is given. According to their own power consumption features and the reliability pricing published by power grid， the power consumers declare the demands of power supply reliability. And then the power grid company determines the reserve capacity according to the power consumers’ demand. The new mechanism proposed can satisfy the individualized reliability demands for reliability and is apt to be received by the power users and easy to be carried out.