Bacterial strain, Halophilic bacterium JAS4, capable of degrading endosulfan and its metabolites was isolated from Gossypium herbaceum rhizosphere soil by enrichment technique, considering the fact that the microorganism had adapted to exposure in pesticide after having been in contact with pesticide contaminated soil. The JAS4 isolate had remarkable potential to degrade 1000mg/l of endosulfan by catabolic activity and transform them into simpler compounds. The biodegradation experiments showed that α,β-endosulfan and endosulfan sulfate in the aqueous medium was degraded by JAS4 strain which was characterized by the rate constant (k) of 0.017d-1, 0.003d-1, and 1.219d-1, respectively. The period within which the initial pesticide concentration was reduced by 50% (DT50) was 40.7d (α-endosulfan), 231d (β-endosulfan) and 0.5d (endosulfan sulfate). Inoculation of sterile soil with Halophilic bacterium JAS4 and nutrients enhanced the disappearance rate of pesticide, and DT50 for α,β-endosulfan and endosulfan sulfate was 0.01d, 346.5d and 1.07d, respectively. In the present study powder formulations were prepared by two methods; they are less expensive and handling is also easy. © 2014 Taiwan Institute of Chemical Engineers.