A method for judging feature of malignant tumor is described. The method comprises obtaining step, first comparing step, second comparing step and judging step. The obtaining step comprises obtaining a first parameter based on activity and expression level of a first cyclin dependent kinase (first CDK) contained in a tumor cell of the malignant tumor, a second parameter based on activity and expression level of a second cyclin dependent kinase (second CDK) contained in the tumor cell, a third parameter based on the first parameter and the second parameter, and a fourth parameter based on expression level of a cyclin contained in the tumor cell. The first comparing step comprises comparing a first threshold value with the third parameter. The second comparing comprises comparing a second threshold value with the fourth parameter. The judging step comprises judging the feature of the malignant tumor based on the comparison results of the first comparing step and the second comparing step.