A structural damage alarming method is proposed using empirical mode decomposition. The intrinsic mode functions are firstly obtained from the empirical mode decomposition of structural response signal, and then the energy redistribution of the intrinsic mode functions is used to reflect the variation of the structural dynamic characteristics caused by the structural damage, on the basisof which structural damage indices are calculated. This damage diagnosis is employed to analyze Benchmark model structure proposed by the International Association for Structural Control and the American Society of Civil Engineers (IASC ASCE) Task Group on Structural Health Monitoring. The structural dynamic responses from the hammer impact tests are collected then the damage alarming parameters and the damage alarming indices are evaluated. The experimental results reveal that the structural damage alarming indices based on empirical mode decomposition is able to effectively detect the structural initial damage with preferable damage alarming capacity.