Objective  To characterize "120" emergency medical responses to road traffic injuries in Beijing six urban districts and to investigate the related influential factors to guide the rational allocation of emergency medical resources.Methods  Medical data of road traffic accidents in six urban districts of Beijing in 2010 were collected from Beijing Emergency Medical Center.Case number,emergency response time,and distance between rescue depots to injury scene were analyzed statistically and retrospectively.Results  Incidence of road traffic injuries in Xicheng District ranked the highest (5.19cases/10,000 people) and that in Shijingshan District the lowest (1.25 cases/10,000 people).A strong correlation between incidence of road traffic injuries and population density was observed (Pearson correlation coefficient =0.960,P ＜0.01).Road traffic injuries were more in the day (n =2 000) than in the night (n =1 107)(P ＜0.01).Besides,the injury in Fengtai and Dongcheng Districts was more in commuting period (with M-shaped time distribution),while in Chaoyang district a second increase was observed in 20:00-23:00.Emergency response time was the longest in Fengtai District (15.1 min) and theshortest in Chaoyang District (12.0 min) and Shijingshan District (12.1 min).Distance from emergency rescue depots to injury scene was the farthest in Chaoyang District (5.6 km) and the nearest in Shijingshan District (4.3 km).Conclusions  Road traffic injuries in six urban districts of Beijing differ in aspects of area and time distribution.The "120" emergency responses in each district are varied,so emergency medical resources should be further optimized to help improve the efficiency of pre-hospital emergency care.