Abstract: Three-dimensional turbulent characteristics of the tip leakage vortex inside an axial-flow compressor rotor passage were studied using a 3-Component Laser Doppler Velocimetry.The measurements were conducted in a low-speed large-scale compressor at a low mass-flow condition.The flow was surveyed across the entire passage at fifteen axial locations (leading edge to trailing edge) and twelve radial locations (0.985 to 0.700 spans).The measurement results indicated that strong interactions of the tip leakage vortex and the annulus-wall boundary layer produce high turbulence.The region of high turbulence develops with the leakage vortex.The radial turbulence intensity is the largest of the three components,and the axial-radial Reynolds stress is the largest of the three shear stresses.Breakdown of the leakage vortex happens at about 80% axial chord and makes the downstream flow more turbulent in the larger region.The corner vortex contributes to the high turbulence level at the corner of the tip suction surface.