To increase the fracture toughness of paper made of Sw-BKP, refining and kneading conditions were analyzed. Curl and kink was known to increase the strain at break and the fracture touhness. Sequence of multiple stage beating, beating load and kneading were compared. When we applied a kneading treatment using a kneader at the final step, the most of the fiber transformation such as curl and kink occurred, the more the bulk and air-permeability improved. Physical strength and TEA(tensile energy absorption) were increased higher when kneading treatment before refining than only refining treatment was performed. TEA was increased because of higher elongation. It was found that the highest fracture toughness was obtained when applying the kneading treatment to the fibers in the pre-treatment step rather than in the middle step of beating or in the final step of beating.