In this study, the collapsing simulation for timber house was conducted in order to estimate the seismic damage quantitatively. Wallstat, which is numerical analysis program for timber frame structures, is used for the collapsing simulation. The two-story timber house and 12 observed earthquake waves were used for the simulation. Correlation between the response acceleration and seismic damage, calculated by non-linear state of seismic walls such as elastic, plastic, decreasing strength and loss of strength, was found in the analytical results.