In Shanxi reservoir area of Zhejiang Province,this paper set up 5 survey lines for fault soil gases Rn and H₂,then selected 15 sampling points for dissolved water radon.The results showed that the mean value of Rn concentrations in 3 soil gas lines is over 70 Bq/L,the maximum value of soil H₂ is 1 377 ppm,and the maximum value of dissolved radon concentration in water samples is 68.3 Bq/L.Based on the analysis of historical seismicity and geological structure of the study area,it is found that the high value distribution areas of soil Rn,H₂,and dissolved water radon are closely related to the spatial location of F_11-3 branch of the Shuangxi-Jiaoxiyang fault,which is the seismogenic fault of small earthquakes in the study area.In addition,we also found that the occurrence time,the frequency,and the intensity of historical earthquake swarm are important factors affecting the geochemical characteristics of soil gases Rn and H₂ in Shanxi reservoir area.