In this study, the effects of partition walls into dynamic behavior of reinforced concrete building are investigated with experimental researches. A six-story reinforced concrete building, constructed in 1980s, is used as a test specimen. The dynamic characteristics of the studied building are determined by ambient vibration survey. Later on the partition walls, composed of bricks and cement mortar, are set ineffective by separating them from the frames they fill. The repeated ambient vibration survey gives the dynamic characteristics of the building which does not have partition walls on its ground floor. The comparison of the determined dynamic characteristics for two forms of the same building revealed the contribution of partition walls into the dynamic properties of the building.