A medical image processing apparatus, comprising: a tubular structure extraction means for extracting a coronary artery from a three-dimensional medical image representing the coronary artery; a core line extraction means for extracting a core line of the extracted coronary artery, an index value calculation means for calculating an index value representing a characteristic of the coronary artery in each direction of radial visual lines orthogonal to the extracted core line at each of a plurality of points on the core line with each point as each viewpoint; a characteristic map image generation means for generating a characteristic map image representing the characteristic inside of the coronary artery by mapping the index value calculated in each direction of the radial visual lines at each point on the core line to a coordinate plane defined by a first coordinate component representing a position in a direction of the core line and a second coordinate component representing a direction of each visual line, and wherein the index value calculation means is a means that calculates two types of index values; characterized in that: the characteristic map image generation means is a means that generates a characteristic map image in which either one of the two types of index values is represented in a coordinate space defined by the first and second coordinate components, and a third coordinate component representing the either one of the two types of index values as a coordinate value of the third coordinate component, while the other of the two types of index values is represented by at least one of color, density, and pattern, and the two index values are a stenosis rate and plaque of the blood vessel, wherein the plaque index value is one of an average, maximum or minimum signal value from the viewpoint to the contour of the coronary artery, with respect to each of the radial visual lines; and wherein the stenosis rate index value is based on a difference between the length of the diameter from the viewpoint to the outer contour of the coronary artery and the length of the length of the diameter from the viewpoint to the inner contour of the coronary artery, with respect to each of the radial visual lines. a tubular structure extraction means for extracting a coronary artery from a three-dimensional medical image representing the coronary artery; a core line extraction means for extracting a core line of the extracted coronary artery, an index value calculation means for calculating an index value representing a characteristic of the coronary artery in each direction of radial visual lines orthogonal to the extracted core line at each of a plurality of points on the core line with each point as each viewpoint; a characteristic map image generation means for generating a characteristic map image representing the characteristic inside of the coronary artery by mapping the index value calculated in each direction of the radial visual lines at each point on the core line to a coordinate plane defined by a first coordinate component representing a position in a direction of the core line and a second coordinate component representing a direction of each visual line, and wherein the index value calculation means is a means that calculates two types of index values; characterized in that: the characteristic map image generation means is a means that generates a characteristic map image in which either one of the two types of index values is represented in a coordinate space defined by the first and second coordinate components, and a third coordinate component representing the either one of the two types of index values as a coordinate value of the third coordinate component, while the other of the two types of index values is represented by at least one of color, density, and pattern, and the two index values are a stenosis rate and plaque of the blood vessel, wherein the plaque index value is one of an average, maximum or minimum signal value from the viewpoint to the contour of the coronary artery, with respect to each of the radial visual lines; and wherein the stenosis rate index value is based on a difference between the length of the diameter from the viewpoint to the outer contour of the coronary artery and the length of the length of the diameter from the viewpoint to the inner contour of the coronary artery, with respect to each of the radial visual lines. the characteristic map image generation means is a means that generates a characteristic map image in which either one of the two types of index values is represented in a coordinate space defined by the first and second coordinate components, and a third coordinate component representing the either one of the two types of index values as a coordinate value of the third coordinate component, while the other of the two types of index values is represented by at least one of color, density, and pattern, and the two index values are a stenosis rate and plaque of the blood vessel, wherein the plaque index value is one of an average, maximum or minimum signal value from the viewpoint to the contour of the coronary artery, with respect to each of the radial visual lines; and wherein the stenosis rate index value is based on a difference between the length of the diameter from the viewpoint to the outer contour of the coronary artery and the length of the length of the diameter from the viewpoint to the inner contour of the coronary artery, with respect to each of the radial visual lines.