The experimental sites of this study were in the aquacultural ponds (ponds A, B, C, and D) and the water inlet (I) of the Hsih-Tsao Wildlife Conservation Area, Tainan City. The on-site and laboratory experiments were carried out in this study. In the field, the 304-type stainless steel pans were placed one year in ponds A, B, C, and D and at the water inlet (I) for their corrosion observations. The results revealed that there existed a seasonal change in the corrosion of 304-type stainless steel. In spring and summer, the corrosion of the stainless steel was remarkable, revealing three different kinds of corrosion patterns (formation of red-brown matter, formation of black matter, and appearance of etching). In the laboratory, the experimental results of corrosion tests on the 304-type stainless steel coupon demonstrated that the corrosion was somewhat correlated with salinity. Thus, the bacteria isolated from the adhesives on the corroded stainless pans in ponds A, B, C, D and the water inlet were cultivated in the sulfate-reducing medium with five different salinities (S1: 7.4��, S2: 13.5��, S3: 17.2��, S4: 23.5��, S5: 36.6��), in which the 304-type stainless steel coupon was put in separately. The results showed that the corrosion was marked (loss of weight) while the coupon was in the low salinity medium, whereas the corrosion was not significant while that was in the high salinity medium. This suggests that salinity and microbes can be causative factors of corrosion. In the low salinity medium, salinity and microbes could cause the most severe corrosion of stainless steel, suggesting being a good reference for the anti-corrosion of stainless steel.