Abstract: To address the current challenges including increasing penetration of wind-solar renewable energy sources, drastic reduction of system inertia, poor frequency stability, insufficient overall regulation capability, and source-load spatial mismatch, this paper proposes a coordinated planning method for hydro-wind-solar-pumped storage systems with consideration of frequency security and chance constraints. Firstly, detailed modeling is conducted on hydropower stations, hybrid pumped storage stations, wind power stations, solar power stations, battery storage stations, and DC transmission constraints. Maximization of system net profit is set as the optimization objective, which takes into account electricity sales revenue as well as the construction and investment costs of wind, solar and pumped storage facilities. Secondly, a frequency security constraint model is established, which considers the emergency adjustment of DC power to support frequency stability. Thirdly, to handle the stochastic nature of wind and photovoltaic output, an uncertainty model based on chance constraints is developed, and the robust expansion formulation of sample average approximation is adopted to transform chance constraints for tractable computation. Case study results show that the proposed model effectively achieves a coordinated planning and configuration of hydro-wind-solar-pumped storage. Combined application of chance constraints and frequency security constraints facilitates rational installed-capacity planning from a theoretical perspective to cope with renewable output volatility and system frequency security risks.