New use of ADAMTS13 in the clinical filed is provided. The use of ADAMTS13 as a biomarker for monitoring the onset of liver damage, hepatic ischemia/reperfusion injury or the liver function after liver transplantation: a method of testing liver damage, a method of testing hepatic ischemia/reperfusion injury, or a method of testing the liver function after liver transplantation, each of the methods comprising measuring or monitoring the ADAMTS13 activity in a sample from a mammal； an agent for treating diseases selected from the group consisting of liver damage, hepatic ischemia/reperfusion injury and hepatic dysfunction after liver transplantation, which comprises ADAMTS13 or a mutant of ADAMTS13 as an effective ingredient.
