The wide usages of masonry materials in construction are always accompanied by great consumptions of energy and resource during their life cycle, so it is necessary to evaluate the EI of masonry materials objectively. This paper uses BEPAS, an LCA-based quantitative EI assessment system developed based on our previous studies, to assess the life cycle EI of three kinds of common used masonry materials: autoclaved flyash brick, sintered clay brick and aerated concrete block. Starting with establishing the environmental profiles at the producing, constructing and demolishing phases of these three materials respectively, the environmental impacts are categorized into three safeguard subjects: ecosystem damage, resources depletion and health damage. Then, based on WTP (willingness-to-pay) method and the updated monetization weighting factors, one integrated EI value per functional unit (10m3) of masonry partition wall is obtained. Finally, a comparative study is conducted on the EI values to analyze and compare the life cycle environmental performance of the three materials, resulting that autoclaved flyash brick is the most environmental friendly in a sharp contrast to sintered clay brick. Results also indicate that reusing more wastes, as well as reducing weight and increasing the volume of unit block are the most effective measures to improve the environmental performance for masonry materials.