Abstract: To understand the synergetic features of economy, society, and ecology in cities, we established an urban ecological-economic-social synergetic index evaluation system from three aspects (per capita green area, per capita GDP, and life expectancy per capita) and created an urban ecological-economic-social synergetic index eva-luation method. We analyzed the synergetic features by comparing the ecological-economic-social synergetic index and comprehensive function scores of 35 typical cities in China. The differences in ecological-economic-social synergy and function score for different city sizes and administrative divisions were investigated, while the synergy level of cities were classified. The results showed that the average ecological-economic-social synergetic index of 35 cities in China was 28.79, with the highest of 3.83 and the lowest of 63.04 in 2016. The synergetic index, urban econo-mic function, and social function were significantly positively correlated with urban population sizes and economic sizes. There were significant differences in synergetic index among cities with different population sizes, economic sizes, and administrative functions. The urbanization in China was still in the status of functional imbalance. Urban development was conducive to improve cities' function, but did not effectively improve the synergy of ecology, economy, and society. The ecological function of cities significantly affected urban synergy, which indicated that the poor urban ecological function was the main restrictive factor for urban synergy in China.

Key words: urban function synergy, ecology, economy, society