A medical image processing apparatus includes a core line identifying unit that identifies a core line of a predetermined region of a tubular structure from medical three-dimensional image data, a center position identifying unit that identifies a center position of the tubular structure from a plurality of points forming the core line identified by the core line identifying unit, an obtaining unit that obtains positions where straight lines intersecting at the center position and the tubular structure in the medical three-dimensional image data are in contact with each other, and a calculating unit that calculates a length of the tubular structure based on the positions obtained by the obtaining unit.