This paper is intended to present a model for describing the dynamics of actual wood volume damaged by the pine wilt disease. Applying the KERMACK-MCKENDRICK epidemic curve (1927), the author derived the simulation model which can be written as follows ;
f(t)=M sech2{k(t-τ)}
where M, maximum of wood volume damaged by the pine wilt disease (m3); k, intrinsic rate (year-l); τ, time of maximum damaged volume (year); t, time (year), and f(t), damaged volume at time t (m3). The simulation model was fitted to observed data of wood volume damaged by the pine wilt disease from 1973 to 1990 in Shimane Prefecture and Hikawa-cho respectively and was tested its applicability.