<p>This paper presents a method of estimating dynamic strain responses on beams in steel moment-resisting frames using limited floor acceleration measurements. First, a dynamic strain estimation method is derived from a model-based state observer in the state space based on shear models of steel moment-resisting frames, in which a base-excited steel frame can be equivalent to a finite element model of the structure with corrective forces and grounded dampers, and thus dynamic strain responses can be directly estimated from the finite element model of structures. Then, the effectiveness of the proposed method is numerically and experimentally investigated using a ten-story steel frame model and a shaking table test of a three-story steel frame specimen. The influences of deployments of the corrective forces and grounded dampers, the number of stories being measured, measurement noise, and errors in structural properties on the estimation results are also investigated. In addition, advantages of the proposed method over a general seismic time-history analysis method and application of the method in detecting damaged beam ends in steel frames are experimentally discussed.</p>