As an international metropolitan area undergoing rapid development, Beijing is facing a sharp rise in the volume ofmotor vehicles andmobility,which has become the major contributor to the air pollution in this city. This is evident in the recent ranking of Beijing as the most congested as well as the most polluted city in the world by the Millennium Cities Database. Local government has adopted a battery of policies to reduce these problems. In this study, we investigate the impact of increasing the fuel tax on travel mode choice based on a large sample of travel survey data. We estimate that if the price of gasoline increased to a moderate level, 11.53 RMB/liter, the total car volume on the road would be reduced by 7 per cent, which corresponds to a reduction in CO2 emissions of 786,002.4 tons, or about 8 per cent of vehicular emissions from private cars and company-owned cars in Beijing.