The purpose of this study was to make a firm and significant intention of children s humor understood by looking deeply for what contents of humors those children of aged from the late four-year-old to five-year-old use, how they change, and how the intention of children s humor telling change in a natural circumstance of a kindergarten. For the purpose, the research questions were as follows: 1. What are the contents of 4-5 years old children s humor and how have they been changed? 2. How were the intents of 4-5 years old children s humors changed? The results of this study were as follows: First, the contents of the children s using humors were characterized generally into five category such as challenging to prohibitions, gaining great pleasure from dirty things, exaggeration, joyful entertainments, incongruity, fresh dilemma, mimicking TV, meeting with boob tube, toddling toward language play. As time passes, the quality and quantity of their humors were improved and used their humors more aggressively. Each content category were seen to be changed through three phases such as, the seeds of humors planted in children were germinated, and sprouted through the humor supporting environment and teacher s humors modeling, and then lastly, the flower of children s humors come into full bloom, that is, humor seeds are germinated, humors sprout are came out, humors flowers come into full bloom in every day lives of children. Second, the change of humor using intention of the surveyed children went through five stages generally. Late four-year-old children s humor using intention appeared starting with simple play which is the beginning stage of this research, following their teacher s humors, making their friends happy, strengthening our solidarity, becoming stars.