In this study, the effects of the Community of Philosophical Inquiry Activities on young children`s philosophical Inquiry were examined. The major purposes of this study were to investigate (1) the effects of the Community of Philosophical Inquiry Activities on the young children`s questions, and (2) the effects of the Community of Philosophical Inquiry Activities on the peer interactions. Thirty three 5 year old children participated. The Community of Philosophical Inquiry Activities based on `Philosophy for Children(P4C)` program were used 4 days, 30 minutes per day, each week for a 10 week duration. The changes of young children`s questions and the peer interactions were analyzed using the protocols of discussions in the first, forth, seventh, and tenth weeks as data. The result of this study revealed that significant quantitative changes in young children`s question and peer interaction took place after applying the Community of Philosophical Inquiry Activities. This findings imply that it is possible for young children to do philosophical inquiry, and the Community of Philosophical Inquiry Activities has the potential to be effective in thinking education for young children.