It is very important to know the load distribution on the line of contact and the tooth root stress of a bevel gear. However, to caluculate these in not easy, because the tooth depth and the tooth thickness get bigger from toe to heel and the meshing of a bevel gear is complicated. Accordingly, studies on these are few. Therefore, before the load distribution on the tooth flank and the tooth root stress of a bevel gear are calculated, the deflection of the fan shaped cantilever under the condition where the concentrated load is placed on the cantilever is calculated, by the method that the fundamental differential eqations derived from the static balance on the minute part of the cantilever is roprcsented in the difference equations and the difference equations are solved.