The influence of varying amounts of S on the soil microflora, as measured by numbers, ammonification, nitrification, azofication, and rate at which S was oxidized to sulphates, was determined. Three types of soil were used, all with low N and S content. Sulphur was added at the rate of 100-1000 pounds per acre. Samples were kept at constant temperature and water content. Small additions of S increased ammonification in soils 50-100%. Large applications of S decreased ammonification. Applications of S decreased nitrification in some soils but produced a marked increase in others; S was without effect on azofication. Bacterial counts varied directly with the S additions in some samples and inversely in others. 36-89 % of the S was oxidized to sulphates in 30 days, depending on the soil and its porosity.