In this study, a scheme integrated with deterministic- stochastic subspace system identification and the method of damage localization vector (DLV) is proposed for damage detection of structures based on seismic response data. A series of shaking table tests has been conducted in National Center for Research on Earthquake Engineering (NCREE), Taiwan. Damage condition is simulated by reducing the cross-sectional area of some of the columns at the bottom ends. Both single and multiple damage conditions at various locations have been considered. Full or partial observation conditions have been taken into account in the system identification analysis. It has been shown that local damages (stories) can be identified from global responses of the structure to earthquakes if sufficiently observed.