Abstarct: In order to study the interaction of sulfur, zinc and Thiobacillus bacterium on yield and yield components of cotton and some soil parameters, a field experiment in a factorial randomized complete block design with three replications was conducted in the mahvelat city. Experimental factors included three levels of sulfur 0, 500 and 1000 kg ha-1, Thiobacillus bacterium in two levels control and used and zinc sulfate in two levels 0 and 50 kg ha-1. Results of analysis of variances showed that, the interaction of sulfur, zinc and Thiobacillus on some agronomic and soil traits including cotton yield, seed cotton yield, boll weight, electrical conductivity and available sulfate were significante at 1% level and plant height and First boll height were significant at the 5% level. According to the comparison results, application of 1000 kg ha-1 sulfur without of Thiobacillusand and zinc also treatment with the application of 1000 kg per ha-1 sulfur with Thiobacillus was caused Significant increase in cotton yield and seed cotton yield compared to the control .Application of 500 kg ha-1 sulfur and also the application of 500 kg ha-1 sulfur with zinc was caused a significant increase in boll weight, but 500 kg ha-1 of sulfur with zinc caused significant reduction in plant height .The Soil traits studied, the application of 1000 kg ha-1 sulfur alone caused a significant decrease in soil pH, but significant increase created in electrical conductivity of the soil, the amount of adsorbed sulfate and the amount of adsorbed zinc. However, application of 500 kg ha-1 sulfur with Thiobacillus more than alone of sulfur created significant increase in the available sulfate and adsorbed sulfate of soil .