The concept of ”ideology” of Marx has been widely referred, discussed as well as commented, but its very contents were seldom exhibited through the text of Marx's own. Therefore, the meaning of both ”critique” of ideology and ”praxis” which related closely to the former could not be adequately understood. Once this be done, it would be recognized that the Marx's ”method” or ”basic character of thought” consists in a duoprocess: one is the theory must be constructed as dialectical development, which starting from a simple and universal category, then the movement of reality can be ideally presented (dargestellt) through it. The other is the simple and universal starting point could neither be self-evident nor in-itself (an sich), but must be discovered through ”critique” or ”research”, that means, depends on the continuous development of the reality. The starting point is hence continuous ”re-starting” and still ”changing” through praxis.