The intermittent nature of wind power challenges the generation expansion planning based on deterministic methodology. By utilizing probabilistic methodology and software， this paper discusses the issue of generation expansion planning with large-scale wind power integration into Jiangsu power grid. System adequacy analysis and optimal generation mix are studied together with the discussion of proper parameters of peak-valley regulation capacity demand for wind power in the optimization. Considering the intense constrains between the source and demand of peak-valley regulation capacity， sensitivity analysis of the capacity between wind power， unclear and pumped storage are carried out. The statistics of power flows across Yangtze River are also calculated to analyze the proper generation location in Jiangsu.