Moral behavior is a human behavior mode with moral value, which can be divided into actional moral behavior, verbal moral behavior, psychological moral behavior, and so on. Human moral behavior is characterized with both phenomenality and regularity. Many people have fallen into the mire of blind moral optimism, moral pessimism or moral confusion because they focus more or only on the phenomenality of human moral behavior, whose nature is their lacking in the correct cognition of the freedom of moral behavior. The freedom of moral behavior is a state in which human beings have got rid of blindness in moral behavior. To obtain the freedom of moral behavior is the fundamental purpose of human moral life, and people without the freedom of moral behavior will have the feeling of “being forced” in the process of completing their concrete moral behavior. In order to obtain the freedom of moral behavior, people’s understanding of human moral behavior must realize the leap-forward from phenomenality to regularity. The law of human moral behavior is the inevitability that dominates human moral behavior. The most general law governing the existence of all things in the world, the natural law governing the evolution of the Nature, the social law governing the development of human society, and the thinking law governing human thinking activities, are all applicable to human moral behavior. Human moral behavior will inevitably form some of its own unique laws in the process of continuous development. Marx believed that human moral behavior should be governed by many laws, but he opposed the practice of attributing these laws to “universal laws” .