北京市经济增长速度、城市化进程、人口密度和机动车的使用量都较其他城市发展得更为迅速，空气颗粒物（PM）污染越来越成为频繁事件，特别是PM2.5的污染尤其引起关注。世界卫生组织（WHO）对空气中颗粒物含量的国际标准是每年不超过7天空气中颗粒物的平均浓度在150-230 之间，空气中颗粒物的年平均浓度少于60-90 。北京市2001—2004年，PM2.5的平均浓度在96.5-106.7 之间，远高于世界卫生组织规定的标准。而近年来该情况越来越恶化，因此，对北京市PM2.5的研究，具有重要的现实意义。 本文首先对空气颗粒物（PM）对健康的影响以及空气污染治理政策效果的经济评估方法进行了梳理，最后选定了成本-效果分析（CEA）方法，并且指出从成本的角度，结合效果的定量分析，有益于注重效果的空气污染治理政策的制定。对个人或整个社会来说，效果的显著，是社会福利提高的显示。成本-效果分析（CEA）方法过去主要用于健康卫生领域中对药物和医疗干预政策的评价，无论对个人，还是对公共和私人医疗服务提供者来说，以价值为导向的决策模式，越来越成为主流和重要的方法。成本-效果分析（CEA）方法常用于进行经济学评价，包含了实用工程学、经济学和运筹学方面的知识，通常通过成本-效果比对研究项目的经济效率进行评价。 本文选取PM2.5作为指示性污染物，以北京市的数据资料为基础，结合人口资料、健康影响函数等，运用成本-效果分析（CEA）方法，将考虑死亡率的生命年（MILY）作为效果指标，估算了北京市治理PM2.5的成本界值，得出结论： PM2.5治理是有其必要的，北京市空气颗粒物（PM）污染状况严重，尤其是PM2.5一直是空气污染中的主要污染源，对居民的身体健康造成了重大的影响；从健康效应终端来看，北京市PM2.5治理带来的健康效应中，对早逝的影响明显，通过测算得出PM2.5的浓度每减少10 ，可以减少3339.07例的过早死亡、增加159309.5的生命年，相对于每一质量调整生命年值210000元的标准来说具有成本效果的治理成本界值334.55亿元。 因此，在本文的计算中，我们认为只要PM2.5浓度每减少10 的治理成本小于334.55亿元，那么这项政策就是具有成本效果的，在经济学上是有效的。

With the rapid economic development, urbanization, increasing population density and usage of motor vehicles, the pollution haze becomes a big problem in Beijing. The international standard of particulate matter is average 150-230 every seven days, average 60-90 every year, but the concentration in Beijing is 96.5-106.7 , much higher than the standard. Furthermore, the situation is getting worse these years. Thus, the research of PM2.5 has important realistic meaning.This paper firstly reviews the literature of effect on health of particulate matter and research method for economic effectiveness of air pollution reduction policy, and then selects the method of Cost-Effective Analysis (hereinafter referred to CEA). which uses quantitative analysis and considers cost. This method helps make environmental policies. Significant effect indicates the improvement of public welfare for individuals and society. CEA is often used to evaluate the efficiency of medical intervention policies in the area of health and hygiene. Value-based decision-making pattern has become more and more mainstream and important for public and private medical provider. CEA includes the knowledge of practical engineering, economics and operation research and always uses the cost-effect ratios to evaluate the economic efficiency.Using PM2.5 as directive pollutant, based on the data in Beijing area, combining population data and health impact function, this paper uses Mortality Inclusive Life Years (hereinafter referred to MILY) uses CEA to calculate the upper limit of pollution control cost. The conclusions are as follows:It is necessary to control the PM2.5 as the pollutant is severe in Beijing, and PM2.5 is the main pollutant in air and harms health; PM2.5 control is beneficial to the health of people in Beijing area. Every 10 microgram of ambient PM2.5 reduced will result in 3339.07(95%CI）premature deaths avoided, 159309.5 undiscounted life years gained. Current PM2.5 control costs of up to 33.45 billion yuan per 10 microgram are cost effective relative to a benchmark of 210000 yuan per QALY.Therefore, we consider that the policy is cost-effective in economics as long as the control costs are less than 33.45 billion yuan.