Abstract: The behaviour differences between connections and elevated temperatures and the corresponding design requirements of a steel structure are illustrated. It is pointed out that direct application of the design concept for the ambient temperature to a fire safety design is unreasonable because in a fire situation, robustness should be the main concern for connections. The observations and conclusions drawn from a set of tests designed for this purpose are then reported. The relationships among three major parameters in a connection design, i.e., the moment capacity, the axial force capacity and the rotational capacity of the connection are discussed and a solution for a performance-based connection design is proposed.