Abstract: The corrosion fatigue performance of welded joints of homemade 2205 duplex stainless steel (DSS) has been studied in simulated seawater environment. The S-N curves of corrosion fatigue life were obtained at different environment temperatures of 24,30 and 40℃,as the stress ratio is 0.1 and the loading frequency is 20 Hz. The experimental data shows that the low stress level had a significant effect on the fatigue life as environment temperature rising. Then an S-N mathematical model with temperature was established and welded joint fatigue limit was obtained in simulated seawater environment.