Abstract: Using the method of life cycle assessment (LCA), energy consumption and environmental emissions for biodiesel production from Swida wilsoniana oil and waste cooking oil in its life cycle were quantitatively analyzed, and the result was compared with conventional diesel. The results showed that the emissions of CO, NO_x, HC, and CO₂ in the use of biodiesel from above two materials presented the highest percentage, and the SO_x emissions was mainly from the planting cycle and production cycle. The energy consumption in the life cycle of biodiesel from above two materials were higher than that of conventional diesel, the CO₂ emissions reduced significantly, the emissions of NO_x and HC were higher than that of conventional diesel, and the emissions of CO and SO_x by biodiesel were equivalent to that by conventional diesel. The energy consumption and environmental emissions in the life cycle of biodiesel from two materials showed no obvious advantages comparing to traditional diesel, but the clear advantages in CO₂ emissions and waste utilization.