Abstract: Combining research achievements on environmental literacy at home and abroad, it is suggested that the concept of environmental literacy should mainly include three aspects including environmental knowledge, environmental action and environmental awareness. Based on this concept and the principles of correlativity, terseness and ability to operate, the construct assessment index system of environmental literacy in three stages and four layers was developed by a mathematical assessment model. A few examples were given to verify the model. The importance of application of modern research methods and communication improvement was discussed in promotion of environmental literacy.