Abstract: A titanium tube of condenser in power station fractured during steam turbine test. In order to find out the fracture mode and cause, macro examination, SEM analysis and material examination were carried out. The test results show that the fracture mode was high-cycle fatigue fracture, and the crack initiated from the weld of the titanium tube. The fracture of the titanium tube was related to the excessive amplitude caused by steam impact. Similar failures can be effectively avoided by installing the protection plate.