Generally an equivalent uniform load is considered for wagon loads of a forest railway bridge. We classified such equivalent uniform load into several groups relating to bogie or single car and method of coupling. As reported in the 1 st report, locomotive load appointed 12 t, 10 t and 5 t same as the regulation of the FRS and wagon load gained 0.8 t/m_??_2.5 t/m as the result of calculation. Graphs which drew allowable bending moment for live loads and extreme maximum bending moment for the FRS' loads show safety beams for some definite loads and spans.