Urban green space (UGS) is important in urban systems, as it benefits economic development, ecological conservation, and living conditions. Many studies have evaluated the economic, ecological, and social value of UGS worldwide, and spatial optimization for UGS has been carried out to maximize its value. However, few studies have simultaneously examined these three values of UGS in one optimization system. To fill this gap, this study evaluated the economic value of UGS in terms of promoting housing prices, its ecological value through the relief of high land surface temperature (LST), and its social value through the provision of recreation spaces for residents within a 255 m distance. Subsequently, these three values were set as objectives in a genetic algorithm (GA)-based multi-objective optimization (MOP) system. Shenzhen was taken as the case study area. The results showed that the influencing distance of UGS in Shenzhen for house prices was 345 m, and the influencing distance of UGS for LST was 135 m. Using MOP, the Pareto solutions for increasing UGS were identified and presented. The results indicate that MOP can simultaneously optimize UGS's economic, ecological, and social value.Sustainability 2020, 12, 1844 2 of 18 effects [16,17], absorbing particle air pollutants, improving air quality, infiltrating storms [18][19][20], reducing noise levels [13], and sequestering carbon [21].The social and ecological value of UGS is widely accepted, while its economic value is not as immediately recognizable, because the services it provides are public goods without market prices [22]. However, real estate markets in developed countries and regions with good environmental quality indicate that many people are willing to pay more for urban properties that are close to UGS [23,24]. Many studies have estimated the economic value or amenity benefits of urban parks and public open spaces [22,25,26].In summary, UGS has high social, ecological, and economic value. A comparative plan for UGS is essential for increasing the ecological and socioeconomic benefits of urban development [27]. To date, many studies have examined the spatial optimization of UGS to maximize its value. Huang et al. [27] used a space optimization strategy to improve the quality and accessibility of green spaces and proposed that this optimization method should be used in UGS planning and management. Zhang et al. [28] developed a multi-objective model to evaluate the diurnal cooling of UGS and identify the best locations and configurations for new UGSs. Unal and Uslu [29] attempted to minimize the distances between people and UGS service areas to optimize UGS. Yoon [30] used a multi-objective model to maximize the cooling effect and connectivity of UGS.Even though the spatial optimization of UGS has often been considered in urban planning research, existing studies typically consider only one function of UGS in their spatial optimization processes, such as its social function (through maximizing accessibility) or ecological function (through maximizing...