The breeding behavior was obserbed only once in Hiroshima by the Asa Zoo. A female deposits 500-600 eggs for two or three hours and a large male guards the nest until hatching. They become sexually mature in capitivity about 10 years. They have a long life about over 70 years. This species mainly distributed in the Chugoku Mountains above elevetion 300-700m.
Some adults occur from costral part on rare occations.
Most of their streams made to something improve. Adults have narrow live on the bad condition streams. However, it is doubtful whether they breed. Japanese giant salamanders were important a source of food for mountain people until several years ago. It is said that the taste is like a ray or a shark.