The use of elemental sulfur is of special interest in Iran since most soils are calcareous and elemental S, as a byproduct of the petroleum industries, is readily available. Recently the National Petrochemical Company ( NPC) of Iran, has produced an agricultural sulfur (AS) that contains 90% pure sulfur and 10% bentonite . As the production of this compound is in the experimental stage, relatively little information is available on its disintegration and subsequent oxidation to sulfate in the salt-effected calcareous soils. The present study was initiated to improve the understanding of the disintegration rate of AS in soil, base on determination of changes in some of the chemical properties. Six soil samples were collected from different sites of a dry region of Fars province of southern Iran and AS produced by NPC of Iran, was thoroughly mixed with 2kg of soil at the equivalent rates of 0,2,4 and 6 ton per ha. The samples were incubated under room temperature and moisture content of field capacity for 8 weeks. And pH and EC values as well as sulfate, total nitrogen (N), phosphorous (P), Iron (Fe), manganese (Mn), zinc(Zn), and copper (Cu), concentrations were determined. The results showed that the disintegration rate was very low, and only 1.5, 2.3 and 2% of the applied AS levels (i.e., 2, 4 and 6 ton per ha) were oxidized to sulfate, respectively. The results of pH and EC values in AS level, resulted in no signification changes in the nutritional constituents (except Mn) of the tested soils. To study the hydraulic conductivity under saline-sodic conditions the soils were dried , ground, and passed through a 2-mm sieve. Columns of soil samples were saturated with solution of 100 meq ( ) with sodium adsorption ratios (SARs) of 5, 10, 15 and 20 and subsequently leached with distilled water. The "Sensitive Index" or SI concept was used to obtain a very general index of the magnitude of structural deterioration and reduction in the HC of the tested soils. In general (1) regardless of SAR level and AS rate, the SI values, the percentages of expansion and dispersion of the soil columns leached with different saline-sodic solutions, were different for tested soils, Increases in SAR level resulted in decreases in the SI values and initial height of soil columns; but although , increase in the SAR level from 5 to 10 resulted in decreases in the percentage of dispersion , there was no significant difference between the effect of SAR 10 and SARs 15 and 20 . (2) Application of AS resulted in no significant ( statistical ) effect on the SI values of the tested soils, but was associated with ( somehow) a modifying effect of the degrees of expansion and dispersion of the soil columns, which indicated the improving effect of A.S application on the structure of tested soils under saline-sodic conditions. The multiple regression equation equation between SI values and swelling /dispersion, as well as the mineralogy of tested soils, all suggested that , the slaking of the structure ( due to both swelling and dispersion processes) was responsible for reduction in the SI values ( i.e., HC) of the tested soils.