To study the material behaviors of hot-rolled circle hollow austenitic 304 stainless steel members applied widely in large-span roofs, both smooth and notched round specimens were cut from Φ216×16 mm tubes and tested under monotonic tensile and cyclic axial loadings. Stress-strain curves were obtained to determine basic material parameters as well as load-displacement hysteretic responses and skeleton curves. In addition, fracture micromorphology of the specimens was observed. It is shown that the properties of middle thick austenitic 304 stainless steel are not significantly influenced by hot-rolled forming process. The stainless steel exhibits extensive strain-hardening and higher energy dissipation capabilities under cyclic loadings. As a result, kinematic-isotropic composite hardening material model should be adopted to simulate nonlinear response of this material. Cyclic hardening material parameters are calibrated by test results and used well in the numerical simulations.However, the fracture micromorphology characteristic of the stainless steel is quite different from that of low alloy or carbon steel.