This chapter discusses the relationship between children and money in developmental psychology researches. It summarizes the four maxims of developmental psychology for money. First, it is not predicated on the homo economics as rational economic decision-makers. Second, in analyzing children's understanding and knowledge of money, such understanding and knowledge should be always discussed in association with children's life-world, instead of separating from it. Third, it is not predicated on a neutral money goods exchange system in market economy, but should be analyzed in the social context with its own cultures and histories. Fourth, developmental psychology for money inquires how children would appropriate money as a cultural tool and change their participation in their societies through the appropriation. The chapter explores how they would form new culture through implementation of such activities, instead of inquiring how children would understand money as a neutral tool which functions in a market economy system.