A medical image processing device includes a port, a user interface, a processor and a display. The port acquires volume data of a biological body. The user interface receives designation of two or three regions in the volume data. The processor generates a color volume rendering image based on the volume data and the two or three regions. The display displays the color volume rendering image. The two or three regions overlap each other on a virtual ray on at least one point in the color volume rendering image. The color volume rendering image has a feature that, the color volume rendering image is separable to two or three volume rendering images corresponding to the two or three regions, by a reversible transformation.