In order to study the characteristics of soil seed banks of soil slope and soil-rock slope in mountainous area of Beijing, species composition, density and the relationship between soil seed banks and the above ground vegetation were analyzed. Field surveys backed with indoor germination experiments were conducted in three different areas of Beijing, Jiufeng Forest Park, Mount Baihua and Mount Yunmeng. There were found 54 species, which belonged to 26 families,53 genera, in which there were 23 herbs,18 perennial herbs, took the percentage of 78.2. The density of seed was between 16166.67±2165.16~20612.50±2717.32 seed/m2. There was no significant difference of seeds between 0-5cm and 5-10cm for soil depth. Some vertical trends were found for the seed distribution. The density of seed was higher in 0-5cm of soil depth than 5-10cm of soil depth. There was no significant relationship between seed and above-ground vegetation. Similarity coefficient of species composition between soil seed banks and above-ground vegetation were no high, which were between 0.390~0.492.From this study we found that various seed located in the study area. In addition, high diversity of species helps seed to grow under proper conditions. It can be considered to play a role in the environmental restoration of slope in Beijing area as soil replacement.