Abstract: High temperature mechanical properties of 5 automobile steel grades produced by the EAF steelmaking workshop of Shijiazhuang Iron & Steel Co. Ltd. (Shigang Steel) were investigated by the classical thermal simulating method. Hot ductility and strength curves of these steels were measured with a hot stress/strain test machine. Results in different sampling ways for blooms and a comparison with other results were discussed. The embrittlement and fracture mechanisms o~ these respective steels were clarified based on examination to the fracture surface of specimens with scanning electronic microscope. The relation between bloom quality and high temperature mechanical properties was discussed.