Traditional urban construction often prioritizes grey infrastructure while neglecting the natural functions of ecosystems, exacerbating climate change issues. In response, green infrastructure (GI) has been developed and adapted as a nature-based solution (NBS) and has been proven to provide various ecosystem services including reducing flood risk and mitigating the climate change, which contributes to urban resilience. Currently, most Chinese cities still rely on grey infrastructure, and relevant studies remain limited and usually substitute the term ‘sponge city’, which can lead to a conceptual deviation from the concept of GI. Additionally, there is a lack of comparative research on the application of GI in areas with different development conditions within cities, such as newly developed districts versus historic urban areas. To fill in this gap, this study employs a combined qualitative and quantitative method that covers literature review, ArcGIS analysis, and survey questionnaires to examine the adaptability and effectiveness of GI in terms of stormwater management in newly developed district (Suzhou Industrial Park) and old district (Gusu District) in Suzhou. The expected outcomes could be the identification of GI distribution, categories, and effects in terms of stormwater management in the two districts. Finally, this paper proposes potential optimization strategies based on Suzhou’s experience to other cities within the Yangtze River Delta.