Abstract: As one part of the research project regarding seismic characteristics of the multi-storey RC-masonry mixed structures with less internal longitudinal walls,the dynamic characteristics of two buildings──the No.23 building,Hua Wei district and a 1/4 scaled model have been investigated by vibration tests.Analysis has also been carried out on the factors affecting the foundamental period of this kind of structures. Based on the results of the tests and analysis, some suggestions have been produced in this paper.