A blood vessel dissecting device is disclosed, which includes at least two dissecting devices, which are inserted into a living body along a blood vessel to dissect tissue in a direction of alignment thereof with the blood vessel. The at least two dissecting devices include a first dissecting device and a second dissecting device. The first dissecting device and the second dissecting device are disposed juxtaposedly in the living body, and a branch vessel branched from the blood vessel is located between the first dissecting device and the second dissecting device.
