Abstract: 【Objective】To clarify the influence mechanism of sulfur （S） and lead （Pb） treatments on the rhizosphere soil water content and the microbial counts in the hyperaccumulator Sedum plumbizincicola.【Methods】A pot experiment was established with sulfur concentrations （0,50,100 mg/kg） and lead concentrations （0,200,400,800,1 600 mg/kg）,and interactive treatments of the two were performed. The water content and pH value of rhizosphere soil,the dynamic changes in sulfur and lead contents and their effects on the bacterial,fungal and actinomycete counts were analyzed,and the correlations among the indicators were examined.【Results】With the increase of lead concentration,the soil water content overall showed a trend of first decreasing and then increasing,whereas the soil pH value showed a trend of first increasing and then decreasing;the bacterial count first decreased and then increased with the increase of sulfur concentration under the lead treatments of 0,200,400,800 mg/kg;the fungal count decreased with the increase of sulfur concentration under the lead treatments of 0 and 1 600 mg/kg,and first decreased and then increased under the lead treatment of 200 mg/kg;the actinomycete count decreased with the increase of sulfur concentration under the lead treatments of 0 and 1 600 mg/kg,and first decreased and then increased under the lead treatments of 200 and 800 mg/kg. Correlation analysis showed that soil water content was significantly positively correlated with the fungal count and actinomycete count（P<0.05）;sulfur content was extremely significantly negatively correlated with the bacterial count（P<0.01）,and significantly negatively correlated with the fungal count（P<0.05）;lead content was extremely significantly positively correlated with the actinomycete count（P<0.01）.【Conclusion】Under the combined treatment of 100 mg/kg sulfur and 200 mg/kg lead,the bacterial count in the rhizosphere soil of S. plumbizincicola is the highest,and the soil remediation potential is relatively good,indicating that appropriate sulfur addition can improve soil water conditions and alleviate the inhibition of lead on microorganisms.

Key words: Sulfur, Lead, Sedum plumbizincicola, Soil, Water content, Microorganisms