Air brake system of KTX effectively distributes air to brake panel in each bogie. System consists of carrying bogie brake panel, motor bogie brake panel, driver"s valve panel, pneumatic auxiliary panel and other accessories. For the prove endurance, confirm test number. Distributor and control moderable magnet valve are 500,000 times and respectively, carrying bogie MR/BP cut-out cock are 12,000 times. Tests satisfy all of condition until now. Developments conduct a performance test to brake tester of domestic manufacturer and operating authority.