Abstract: The method of Life Cycle Assessment（LCA）of vehicle energy is more systematic and comprehensive than Environmental Impact Assessment（EIA）that is generally only applied in the phase of energy consumption， but in comparison of vehicle alternative fuel，because of the particularity of operating environment of vehicles， which will lead to great difference of environmental damage by the same quantity of pollutant in different phases，the traditional LCA can’t assess the environmental effects of different vehicle alternative fuels exactly. Therefore， based on summarizing LCA of vehicle fuel，this paper puts forward weight coefficients in different phases calculated in terms of the marginal environmental damage cost，and improves the method of LCA of vehicle fuel，to make it adapted to appling in comparative analysis between different environmental impacts of different vehicle alternative fuels. Finally，a demonstrative analysis is carried out between fuel cell vehicle and gasoline vehicle.

Key words: LCA, vehicle alternative fuel, marginal environmental cost

摘要： 车用能源的生命周期评价（Life Cycle Assessment，LCA）较一般仅对能源使用阶段的环境影响评价方法更为系统和全面，但是在进行车用替代燃料比较研究中，由于机动车使用环境的特殊性，造成等量污染物排放在不同阶段所造成的环境损害差异悬殊，传统的LCA 方法无法准确评价不同车用替代能源的环境效应. 为此，论文在总结车用燃料生命周期评价的基础上，提出基于边际环境损害成本计算分阶段权重系数，进而对车用燃料LCA 评价做出改进，使其适用于不同车用替代燃料之间环境影响的对比分析，并选择燃料电池车与汽油车进行了实证分析.

关键词: 生命周期评价, 车用替代燃料, 边际环境成本