Ambient vibration tests were conducted on wood houses constructed in a traditional manner in Kyoto to estimate their natural frequencies and vibration modes. The ambient vibration tests can be used as a simple method for evaluating their seismic capacity. To establish a method, it is important to grasp the factor affecting the estimated vibration characteristics and variation range of the estimated natural frequency. We evaluate (i) base shear coefficient, (ii) finishing materials of houses, (iii) adjoining house and (iv) seasonal variation, as affector to vibration characteristics. As a result, (i) there are significant correlation between estimated natural frequency and base shear coefficient, (ii) modern finishing materials can change their relation, (iii) adjoining house also effects on natural frequencies and vibration modes and (iv) the range of seasonal variation of natural frequency is 5-10%.
