Abstract:The present paper is a study of the SO2 elimination capacity of some plants in Taiyuan to assess the biological elimination parameters in the environmental atmospheric capacity in the city. The study includes three parts. 1) Investigation on the annual biomass of plants; 2) Determination of the SO2 absorptive intensity of plants and the period of SO2 absorption-transformation-transportation by their leaves by means of simulated fumigation; 3) Assessment of the total SO2 elimination capacity of the plants in this area.In Taiyuan, the biomass of tree leaves is 180,000 tons per year and their average SO2 absorptive intensity is 1.89%. The period of SO2 absorption-transformation-transportation of the leaves is about 30 days, and the activity duration of the leaves is 90 days, three times as long as the period.. Therefore, all the trees in Taiyuan can absorb about 10,000 tons of SO2 every year.In the suburbs of this city, the crop biomass is 250,000 tons per year. The absorptive intensity is 0.45%, The period of SO2 absorption-transformation-transportation is 20 days. The activity duration of crop is about 40 days, two times the period. So the crops in the suburbs could absorb about 2,000 tons of SO2 per year.The total amount of SO2 absorbed by both trees and crops, about 12,000 tons,is regarded as the total SO2 eliminating capacity of the plants over the area every year. Within the investigated range of 525 square kilometers, the maximum average potential SO2 eliminating capacity of the plants is 24.0 tons/sq.km/year.The results suggested that the elimination of SO2 from the air with, plants is an economic, convenient and effective way, in addition to treatment of pollution sourses and control of pollutant discharge.