Using green waste as the material and typical urban green space soil in Beijing as the research object, four treatments were applied: CK(no mulching), BL(wood chips+litterfall mulching), SC(wood chips+semi-decomposed green waste compost mulching), and MC(wood chips+decomposed green waste compost mulching). The effects of green waste mulching on soil aggregates and organic carbon in urban green spaces were then assessed. The results showed that after 18-month green waste mulching, the mass fraction of soil macroaggregates(<2-0.25 mm)(30.77%-40.10%), the mean weight diameter of aggregates(0.42-0.51 mm), and the geometric mean diameter(0.18-0.23 mm) increased significantly, while the fractal dimension(2.64-2.68) decreased significantly, indicating that soil structural stability increased. The mass fraction of organic carbon in soil macroaggregates and its contribution rate to total soil organic carbon increased significantly. Among all treatments, the MC treatment showed the most significant improvement effect. The mass fractions of soil bulk density, soil organic carbon, total nitrogen, alkaline-hydrolyzable nitrogen, available phosphorus, and available potassium exerted significant effects on the formation of soil aggregates and the mass fraction of soil organic carbon. In conclusion, green waste mulching improved the physicochemical properties of urban green space soil, promoted the formation of soil macroaggregates, increased the organic carbon content and its contribution rate of macroaggregates, thereby enhanced soil structure and its stability. Under the conditions of this study, the mulching scheme of wood chips combined with decomposed green waste compost showed the greatest overall effectiveness.