Abstract: Based on fire plume models, the smoke temperatureabove the fire source at different heights was predicted for typical firescenarios of Beijing National Stadium of Olympics 2008. The strength and modulus ofelasticity of steel under different temperatures were considered todetermine the critical temperature value. Accordingly the fire hazard region for steel structures in Beijing National Stadium ofOlympics 2008 was determined to be with in 10.2\,m above the seats.