The present work is aimed at evaluating the vulnerability and seismic behavior of buildings, for which an exciter of eccentric mass has been developed. A card for data acquisition and a software for the digital processing of the vibration signals have been designed, and with the aid of an accelerometer and a varier of speed we were able to obtain the dynamic characteristics of the building under test. The immediate goal is to design and construct an electronic unit to produce and to measure vibration in structures of civil construction on accommodation ladder, with the object of being able to know the dynamic characteristics so as to make the corresponding decisions. The second objective is to approximate the response of the structure to a vibration. The third objective, from the point of view of structural analysis, is to offer to specialists the parameters that would allow them to make decisions and to evaluate the structure under test. The fourth objective is to propose a prototype to specialists, such as an alternative methodology to evaluate the seismic risk of the constructions of experimental way and on accommodation ladder, which specialists can determine if such prototype can be serve their purpose. © 2010 IEEE.