Research purposes : The degree of side slope of mountainous highway should be chosen with consideration of the local ecological environment for the purpose of reducing the influence of highway construction on the local ecological environment.
Research conclusions ： How to choose slope degree becomes a hot study issues at present. With considerations of many factors of deciding the slope degree, slope stability, construction cost and ecological environment, the slope evaluation index and model for the slope degree are presented by adopting subject and object evaluation method. The engineering practice indicates the slope degree decided with this method is reasonable, which can reduce the influence on environment effectively.