Rising inequality threatens the improvement of human well-being. As an important type of green infrastructure within cities, urban green spaces provide ecosystem services and contribute to human health. The inequalities of per capita urban green space area and ecosystem services are critical environmental justice and public health issues but are not well understood. Based on the spatial patterns of green spaces, land rent, and the population of 20 cities in China, we assessed the inequalities of per capita green space area and ecosystem services by using the Gini coefficient. Results showed that (1) the Gini coefficient (an indicator to measure inequality) of per capita available ecosystem services was 0.430, which was greater than that of per capita green space area (0.357), (2) the inequality of per capita ecosystem services had a negative relationship with city size measured by population and GDP, and (3) the inequality of green space area was negatively related to the subjective quality of life, while the inequality of ecosystem services was negatively related to the economic competitiveness of cities. We suggest that urban planners comprehensively consider multiple indicators (such as per capita green space area, Gini coefficients of per capita green space area, and ecosystem services) to simultaneously evaluate the efficiency and equality of green space construction.