A laser tip, a laser treatment tool, a laser treatment device and a laser treatment system are provided for performing laser treatment surgery and minimizing any bleeding. A laser tip is attachable to a laser radiation opening located at the tip end of a laser transmission tube. The laser tip includes an attaching portion detachable from the laser radiation opening and a contact portion contactable with biological tissue. The contact portion is at the front of the attaching portion in the direction in which the laser light exits the laser radiation opening. An open space is located between the contact portion and the attaching portion, and a coupler couples a part of the contact portion and a part of the attaching portion. The contact portion has a reflective surface at a rear end thereof which reflects the laser light toward the coupler.