Abstract: Life cycle cost analysis (LCCA)，according to life cycle thinking，is a systematic methodology，which assesses the environmental and economic performance of products through estimating the monetary value of environmental impact in their whole life cycle and checking their internal cost. Base on the model of life cycle cost，two indices of product greenness factor and greenness ratio were presented，which provided measurable indices for selecting alternatives or comparing the performance of different products. In this paper，LCCA was used to systematically analyze the economic and environmental performance of acetylene produced from natural gas. The results showed that LCCA could identify the main elements which affected the holistic performance of the process，and select the best process from alternatives.