Abstract: A combination of ¹³⁷Cs and ²¹⁰Pb_ex tracing is applied to ascertain the background value and change characteristics of ¹³⁷Cs and ²¹⁰Pb_ex, soil erosion rate, distribution characteristics and main influencing factors of the East-West transects of the Three-RiversHeadwaters region of the Tibetan Plateau. The results indicate that: (1) in the East-West transects of the Three-Rivers Headwaters region of the Tibetan Plateau,the background values of ¹³⁷Cs and ²¹⁰Pb_ex are in therange 453-1，714 and 2，612-7，377 Bq/m², respectively. With changes in elevation of the East-West transects, differences in the background values of 137Cs and ²¹⁰Pb_ex are evident. The regional distribution of 137Cs (x) and ²¹⁰Pb_ex (y) background values shows significant correlation; the equation of the correlation is y3.587，2x+1，463.4, R²0.951，7. (2) The 137Cs tracing result in the Tuotuo River at the Changjiang headstream region indicates that the Changjiang headstream region centered by the Tuotuo River is a typical wind erosion area, with soil erosion rate of 2.5 t/(hm²·a). Thisareais one of the important sources of dust storms on the Tibetan Plateau. (3) The results of ¹³⁷Cs and ²¹⁰Pb_ex tracing in the Maduo typical slope at the Yellow River headstream region indicate that in the last 40 years, livestock-based human activities in Maduo have caused more disturbance to the soil than the impact of natural factors. (4) Comparative study between Dongqinggou andJunmuchang in Maqin indicates that the alpine meadow in Dongqinggou is more effective in soil and water conservation than other vegetation studied, and the animal husbandry activities in Junmuchang have caused serious disturbance to the surface soil. (5) In the Jungongzhen region of Maqin, the ¹³⁷Cs and ²¹⁰Pb_ex results of soil profile from a typical site with serious water erosion show that the lack of ¹³⁷Cs and ²¹⁰Pb_ex was caused by heavy rain during extreme weather events in the region during the 1950s to 1960s.The water erosion caused by the destruction of vegetation in the Jungongzhen region of Maqin is serious; the erosion rate is 8.0 t/(hm²·a). (6) In the past 40 years, increased human activity and global warming have lead to the emergenceof the sand-dust source regions in the Three-Rivers Headwaters region of the Tibetan Plateau.