Taking the scientific view of practice as his theoretic base, for the first time, Marx solved the issue of the relations between subjectivity and objectivity in the philosophy development history of human being. Practice has the nature of both subjectivity and objectivity and the process of practice is a process of the gradual unification of subjectivity and objectivity. Practice is based on recognition and the subjectivity and objectivity recognition is also dialectical. Better recognition of the objective world and the reform of the objective world and better recognition of the subjective world and the reform of the subjective world require the understanding of subjectivity and objectivity in the dialectical unification relations and the using of the subjective and objective principles in the dialectical unification relations.