Moral courage is the courage to be moral and the key to the moral dilemmas. Kidder divides the courage into two strands，physical courage and moral courage，the latter is driven by principle. It is the intersection of three conceptual fields：principles，danger，and endurance. Kidder argues that the moral courage is deontological，not consequentialist. In fact，it is a mixture which including motivation，emotion and consequence. Moral courage can be acquired through the practice gradually，not only a virtue，but also a kind of ability.