Promises express commitments to future actions, and the speaker has the responsibility and the obligation to ensure the realization of the act. At present, the research paradigms for promises include storytelling, resisting temptation and breaking the toy. The related researches on the development characteristics of promises mainly focus on the understanding of the concept of promises, the judgment of the behavior of promises, and fulfillment of promises. The promises may be influenced by the type of question, the identity of the requester, children's moral development level and motivation. Promise plays an important role in children's lies to conceal their own or others' transgressions. In the future, we should narrow the difference between the experimental situation and the real situation, enlarge the scope of the research, explore the moral character of promises, and give full play to its positive effects.