In this paper, we try to estimate the actual yield strengths of reinforced concrete (RC) buildings based on the damage statistics in Kobe surveyed after the Hyogo-ken Nanbu earthquake of 1995 and nonlinear response analyses for synthetic waveforms simulated by Matsushima et al. (2000). First, we construct a set of building models that represents the RC building stock in Kobe and we create a plausible nonlinear multi-degrees-of-freedom models for four different heights of buildings based on the current code and practice. We must assume the damage criterion and the strength distribution a priori. When we calculate the damage ratios for these standard models we find that they are so high that we must increase the average yield strengths in order to match the calculated damage ratios to the observed. The estimated average yield strengths are much higher than those based on the code, especially for low-rise buildings. Using this set of building models we succeed to reproduce the belt-shaped area with high damage ratios in Kobe.