In fire conditions, Concrete Filled Stainless Steel Tubular columns undergo multi-phase fire and loading condition. These are loading at ambient temperature, loading during the heating as the fire accelerates, loading during the cooling phase as the fire intensity gradually declines and loading after the fire. However, limited research has been conducted on fire and post fire behavior of CFSST columns subjected to the entire fire and loading histories. Accordingly, this thesis investigated fire and post fire behavior of CFSST columns in the entire fire and load history. Sequential coupled thermal-stress analysis was utilized to establish the temperature field and the structural response of the columns by using the commercial Finite Element software ABAQUS. Existing fire and post fire test data from literature were used to validate the Finite Element models. Validation was based on the results such as: temperature versus time, deformation versus time, fire resistance and post fire residual capacity. After validation of the test results, the effect of thesis parameters on fire and post fire behavior of Concrete Filled Stainless Steel Tubular columns were examined by using the validated Finite Element Model. Increasing load level from Nf=0.3 to Nf=0.45, decreases fire resistance by 24% and increases the post fire residual strength by 7%. Increasing concrete grade from C30 to C37, decreases the fire resistance by 1% and increases the post fire residual strength by 3%. Increasing concrete grade from C30 to C105, decreases the fire resistance by 11% and increases the post fire residual strength by 8%. Increasing stainless-steel grade from SSG 1.4301 to SSG 1.4311, increases the fire resistance by 12% and increases the post fire residual strength by 10%. Increasing the diameter from 400mm to 600mm, increases the fire resistance by 22% and increases the post fire residual strength by 45%. Increasing the heating time from 15min to 30min, decreases the post fire residual strength by 19%. Increasing the heating time from 15min to 60min, decreases the post fire residual strength by 69%. Increasing the thickness from 10mm to 15mm, increases the fire resistance by 2% and increases the post fire residual strength by 16%. Diameter, load level and stainless steel grade have significant effect on fire resistance. However, concrete grade and thickness have negligible effect on fire resistance. Diameter, thickness and heating time have significant influence, while load level and stainless steel grade have moderate influence on post fire residual strength. However, concrete grade has negligible influence on post fire residual strength. Key words: CFSST columns, fire, post fire, heating, cooling, FEM