A quantification method of the calcifications feature of a tumor, the method being executed by a computer system including a display device, a processor, a memory, an input device and a storage device, the method applying on a gray scale image consisting of a plurality of pixel points and displaying at least one tumor therein, comprising the steps of: retrieving a tumor contour and a tumor contour annular region from the gray scale image, wherein the tumor contour is in the tumor contour annular region; displaying the tumor contour over the gray scale image for defining a tumor inner region and a tumor external region on the gray scale image, wherein the tumor inner region is the region enclosed by the tumor contour; calculating both the minimum value and the standard deviation of the gradient value of the gray scale of the plurality pixel points in the tumor inner region; retrieving a cysts region in the tumor inner region, based on a threshold value based on both the minimum value of the gradient value of the gray scale of the plurality pixel points in the tumor inner region and the standard deviation of the gradient value of the gray scale of the plurality pixel points in the tumor inner region, wherein when one of the plurality pixel points in the tumor inner region has a gradient value of the gray scale smaller than the threshold value, the pixel point is defined to have the cysts feature; and calculating the maximum value, the standard deviation, and the mean value of the gradient value of the gray scale of the plurality pixel points in the tumor inner region but outside the cysts region; and quantifying the calcifications feature of the tumor in the tumor inner region, based on the maximum value and a second threshold value, the second threshold value being based on the standard deviation, and the mean value of the gradient value of the gray scale of the plurality pixel points in the tumor inner region but outside the cysts region, wherein when one of the plurality pixel points in the tumor inner region but outside the cysts region has a gradient value of the gray scale larger than the second threshold value, the pixel point is defined to have the calcifications feature, and calculating the ratio of the region having the calcifications feature over the tumor inner region but outside the cysts region. retrieving a tumor contour and a tumor contour annular region from the gray scale image, wherein the tumor contour is in the tumor contour annular region; displaying the tumor contour over the gray scale image for defining a tumor inner region and a tumor external region on the gray scale image, wherein the tumor inner region is the region enclosed by the tumor contour; calculating both the minimum value and the standard deviation of the gradient value of the gray scale of the plurality pixel points in the tumor inner region; retrieving a cysts region in the tumor inner region, based on a threshold value based on both the minimum value of the gradient value of the gray scale of the plurality pixel points in the tumor inner region and the standard deviation of the gradient value of the gray scale of the plurality pixel points in the tumor inner region, wherein when one of the plurality pixel points in the tumor inner region has a gradient value of the gray scale smaller than the threshold value, the pixel point is defined to have the cysts feature; and calculating the maximum value, the standard deviation, and the mean value of the gradient value of the gray scale of the plurality pixel points in the tumor inner region but outside the cysts region; and quantifying the calcifications feature of the tumor in the tumor inner region, based on the maximum value and a second threshold value, the second threshold value being based on the standard deviation, and the mean value of the gradient value of the gray scale of the plurality pixel points in the tumor inner region but outside the cysts region, wherein when one of the plurality pixel points in the tumor inner region but outside the cysts region has a gradient value of the gray scale larger than the second threshold value, the pixel point is defined to have the calcifications feature,