Some researchers have been studying the strength of joints loaded perpendicular to grain in latest years. Some connections fails in brittle or ductile manner and its fracture features depend on the size of joints and bolt diameter. But evaluation the fracture of wood is very difficult, so some evaluation method was proposed. In the past study, we analyzed the strength of bolted joints with FEM analysis, and we understood that the cleavage fracture stress is useful to evaluate the strength fractured in brittle and that J-integral has a possibility to evaluate the crack initiation. So in this study, we applied J-integral obtained from CT-tests of FEM analysis to bolted joints loaded perpendicular to grain fractured in ductile manner, and the cleavage fracture stress to the joint fractured in brittle manner as same as before. As the results, we can calculate the strength of joints loaded perpendicular to grain by two fracture patterns.