Some analytical studies on a reinforced concrete hotel building, which was damaged beyond repair during the Oita earthquake of April 21, 1975, are presented in this paper. Analysis is started from idealizing the damaged building to a mechanical model. Linear static and dynamic responses of this idealized structure for which lateral motions are coupled with the torsional motion are studied and the influence of the torsional motion on elastic response is investigated. Summarizing the results of these analysis; (1) Ground motion due to the NS component of the Oita earthquake of April 21 1975 was quite severe to this hotel building. (2) Maximum base shear in torsionally coupled system is less than in the corresponding uncoupled system. (3) Effects of torsional motion on horizontal deflection and stresses of the building are not negligible. (4) Equivalent lateral force distribution for static analysis which is specified in the Uniform Building Code is more reasonable than that of the current Japanese Building Standard Law to this building. (5) It will be possible to evaluate the rigidity of the reinforced concrete shear walls by a simple method of analysis.