Pseudomonas aeruginosa ZK (PA-ZK) and Bacillus subtilis S1X (BS-S1X) in the highly saline environment on the surface of the AISI304 stainless steel (SS304). The in-situ corrosion behavior of stainless steel was investigated in both the controlled and inoculated media incubated for 14 days at 37 °C with the help of electrochemical impedance spectroscopy (EIS) and Tafel polarization method. The surface morphology and composition of the biofilm formed on the surface of SS304 were examined by SEM and FTIR analysis.