This paper presents a study on how to accommodate wind power into multiple regions, while simultaneously implementing economic and reliable dispatch for multi-area power system operation. The focus is on quantifying the operational risk brought by wind power uncertainty and at the same time accommodating wind power by coordinating multi-area generation and reserve resources. The reserve requirement of each area is calculated based on two indexes, namely, loss of load probability and wind spillage probability. Then, a generation-reserve cooptimization dispatch model that factors cross-regional wind power accommodation is proposed. The transmission margin and network security constraints of tie-lines are considered to systematically allocate reserve resources for all areas. Finally, optimality condition decomposition is used to decompose the dispatching model to achieve relatively independent regional scheduling, and to get the global optimization result. The reasonableness and effectiveness of the proposed approach is validated by a 6-bus 2-area test system and a 236-bus interconnected system.