1. A method for evaluating/analyzing patent portfolio using patent priorities, wherein the method is implemented to evaluate a patent family by a computer, comprising: (1) selecting, by the computer, the patent family, and establishing a data set based on members of the patent family and priorities claimed by the members of the patent family, wherein the data set is stored in the computer; (2) forming, by the computer, a relationship matrix based on the members of the patent family and the priorities claimed by the members of the patent family in the data set; and (3) analyzing, by the computer, a priority relationship between the members of the patent family and the priorities claimed by the members of the patent family through the relationship matrix, and calculating a generation number and the number of claimed times of priority in the relationship matrix to obtain a critical chain, a significant chain, and a core patent candidate for performing patent evaluation or establishment of patent portfolio, wherein the step (1) comprises: (1-1) selecting one of a plurality of litigation case data that has a greatest case importance coefficient among case importance coefficients of the litigation cases data as important case data, and wherein the case importance coefficient is obtained by multiplying an amount of affiliates in the litigation case data with another size of the members of the patent family.