According to one embodiment, a medical image processing apparatus includes an image storage unit, an estimation unit, a combination ratio determination unit, and a combined image generation unit. The estimation unit is configured to estimate an abundance ratio of one of a first and second substances to the other for each pixel based on attenuation coefficients of the first substance which correspond to a first and second energies, the attenuation coefficients of a second substance which correspond to the first and second energies, and pixel values of a first and second medical images. The combination ratio determination unit is configured to determine combination ratios of pixel values between the first and second medical images for each pixel based on the abundance ratios of the first and second substances and the attenuation coefficients of the first and second substances which are associated with a target energy.