Abstract: In order to work well the ecological protection of the side-slopes of Tangtun expressway, some investigations on the side-slopes soil were carried out. They include soil sampling, pH mensurating, main nutrient index and main trace elements index analyzing. These results shows that the soil was acidic, low organic, lack of phosphor and excessive of copper. Ecological protection of the slopes have the characteristics of steep slope, destruction of original vegetation, leanness of soil, lack of water and fertilizer, drought and heat stress of ecoclimate, severity of soil and water loss. Considered essential principles such as traffic security, environmental harmonization and economical and practical, a new plant configuration of the side slopes was proposed. The herbages were main measure in the slope ecological protection. The herb, the shrub, and the vine were combined as necessary organic supplement. Aiming at rock slopes, fractured rock slopes, and the soil slopes, the coping ,edge and bench of slope, different plant designs were suggested in the paper.