This paper figures out the comprehending of the author through the empathy function of kid playing in real life scenes and the introspection of the author herself when playing, that play mood is the one of deeply relaxed while highly absorbed status.Via the research and apperception on cross-subjects and cross-research fields, the paper indicates that the play mood and peak experience, Samadhi, spirit calming, meditation, afflatus, imagination flowing, relaxed alertness, best learning mood, and best spirit mood, etc., are synonymous status for human. At this status, for its relaxing while absorbed characters, the human brain is on a whole mind; in which the disseverment is removed between consciousness and unconsciousness and person becomes to be a whole existing. This is the most complete, the most essential, the most wonderful, and the happiest whole so that it is the best status for human.The play mood is such a kind of status in which the human' s potential can be spurred to spew out. Its function works on a relaxing while absorbed spirit mood when human brain waves are mainly of α-wave, and each part of brain ( e. g. left brain and right brain, etc) is working hormonally; Disseverment is removed between consciousness and unconsciousness; personal experience, wisdom as well as all human being' s intelligence can be used by person oneself.The play mood is the most creative status for human. Its function relies on, in this mood, that people is staying on whole mind when the brain produces a mass of endorphin which can increase both the speed and efficiency on message transferring between brain cells and make the connection among brain cells very smooth and easy even to produce new connections.The play mood is also the healthiest status both in physically and spiritually for human. Its function relies on, at this status, that people get rid of the separation between consciousness and unconsciousness; the person right now becomes to be the truly representative of himself/herself and at the same time to be bond with the vast and generous human spirits; moreover, the brain begins to excrete β-endorphin (one of the endorphin) and this function can increase the capability of human immunity to keep oneself healthy.The play mood is also one of the self-realization statuses. In such a status,one expresses oneself as a healthful and happy one.The play mood is also the best learning time. The reason is that at this relaxed alertness status, man can learn unconsciously that turns what has just learned to be a long-term memory, and which can be connected with the information learned before.All in all, the play mood we have possessed since the childhood is the best status to exist as a person, which can only be achieved when we release our nerves and in a relaxed mood.Play, is an intelligence to relax ourselves.Teaching works well with inaction while in playing.Knowing how to play will make normal life bright and colorful; life at this time and this moment will achieve an eternal felicity.