In this study, we investigated the biodegradation features of 4 perfluorooctanesulfonate (PFOS) alternatives developed at Changwon National University compared to those of PFOS.Biodegradation testing was performed with microorganisms cultured in the good laboratory practice laboratory of the Korea Environment Corporation for 28 days following the Organization for Economic Cooperation and Development guidelines for the testing of chemicals (Test No. 301 C).While C8F17SO3Na, PFOS sodium salt was not degraded after 28 days, the 4 alternatives were biodegraded at the rates of 20.9% for C15F9H21S2O8Na2, 8.4% for C17F9H 25S2O8Na2, 22.6% for C23F18H28S2O8Na2, and 23.6% for C25F17H32O13S3Na3.C25F17H32S3O13Na3, C23F18H28S2O8Na2, and C15F9H21S2O8Na2 were superior to PFOS in terms of biodegradation rates and surface tension, and thus they were considered highly applicable as PFOS alternatives. Environmental toxicity, human toxicity, and economic feasibility of these compounds should be investigated prior to their commercialization.