Slope collapses of embankment and cut slope along railways are often triggered by heavy rainfall of typhoon, etc. and have much influence on train running safety. It is of vital importance to locate risky sites along the railway to control train operation. For this purpose, it is desirable to develop a practical damage estimation method which can accurately predict the risk of slope collapse and can simply be applied by railway workers in the field. This paper deals with a method of estimating the risk of railway embankment collapse due to heavy rainfall through a multivariate analysis. This paper proposes to define the critical rainfall as a product of the amounts of the accumulated rainfall and the maximum hourly rainfall.