Abstract: A CO2 Emissions-Location Allocation Model Based Public Center Planning Support System (CELA-PCPSS) is developed, which is composed of support layer, data layer, model layer, function layer and presentation layer. Among them, the CO2 Emissions from Car Travel Based Location-allocation Model is the core of model layer and CELA-PCPSS. The major function of CELA-PCPSS is to calculate the optimal location of public center based on low carbon perspective, to simulate the spatial pattern of CO2 emissions from car travel and its total quantity corresponding to different public center layout form quantitatively and visually. Guangzhou is used as a case study. The optimal location of public center and its total CO2 emissions from cars are calculated and the corresponding CO2 emissions spatial pattern is simulated, corresponding to planning 1~6 public centers virtually through CELA-PCPSS. In addition, it is found that the role of creating a new public center to reduce CO2 emissions has a marginal effect. Therefore, in order to maximize the social, economic and environmental benefits, it's necessary to consider economic and social costs and humanistic factors together when the number of public centers is determined and the site location is optimized.