The purpose of this study is to analyse site natural period for estimating resonance of soil-structure. The natural period of seismic accelerometer installed site is calculated with HVSR(Horizontal to Vertical Spectral Ratio) proposed by Nakamura. To analyze natural period, a micro tremor is used at several sites. The result can be used for the study of soil-structure resonance, site classification and the site amplification effects.

The purpose of this study is to consider site effect in order to estimate Soil-Structure and attenuation parameters with a greater degree of reliability. Site amplification is calculated by proposed Nakamura (H/V ratio). The site amplifications using acceleration motion were compared at several sites. The result can be used for the study of site classification and removal of the site amplification effects.