Abstract: Grazing is widely used in mountain land, which changes soil structure through feeding, trampling, excreta return, redistributing solar radiation, surface runoff, and then affects soil moisture and soil elements. However, research of interaction between topography and exclusion duration on relationship between soil and vegetation characteristics is scarce. The study was carried out to explore effect of topography and livestock exclusion duration on soil properties, correlation between soil and vegetation characteristics. The results showed that: (1) Soil moisture peaked at 3 years of exclusion. Water use efficiency, soil organic carbon, soil phosphorus, soil available nitrogen and soil available phosphorus were found to be directly proportional to duration of livestock exclusion and inversely correlated with slope. Soil nitrogen and N/P were directly proportional to duration of livestock exclusion and slope. C/N inversely correlated with duration of livestock exclusion and slope. C/P was directly proportional to duration of livestock exclusion, and the change with slope was not obvious. Soil properties in sunny slope were greater than in shady slope. (2) Aspect and slope positively affected the relationship between soil properties and aboveground biomass significantly. The effects of livestock exclusion on relationship between aboveground biomass, plant species richness and soil properties were insignificant. (3) Livestock exclusion of sunny slope is more beneficial to soil nutrient accumulation than shady slope. Livestock exclusion played an opposite role to topography in regulating the relationship between soil and vegetation characteristics. Therefore, grazing management on complex topography is conducive to regulating soil nutrients and further coordinating vegetation growth.

Key words: typical steppe, topography, duration of livestock exclusion, soil properties, vegetation characteristics