Abstract: Based on the results of vibration fatigue test at ambient temperature by clamping tenon, a failure analysis was carried out to summarize the characteristics of the blade of low pressure turbine. Al1of the blades have two fracture locations: most blades are fractured at the bottom of the tongue and groove which is the high-stress section, and some blades are fractured from the casting defects at the blade body. The vibration fatigue life of the blade at room temperature has a great dispersion, as the fatigue life mainly depends on the contribution of the crack initiation stage. And the size, number and distribution of the thick lamellar structure of the blade will significantly affect the fatigue life and increase the dispersibility of fatigue life. The fatigue performance of the blade at room temperature has a high defect sensitivity. So the presence of Al₂O₃ and Y₂O₃ with a size of about 0.4 mm on the subsurface of the blade body changes the fracture position and initiation mode of the crack. It initiates from subsurface casting defects. And near the source region, intergranular fracture which corresponds to equiaxed grains appears.