Jean Piaget, a Swiss epistemologist, is famous for his research of children's cognitive development. He focuses his study on intellectual development, therefore, his theory is named "theory of intellect" or "theory of intelligence" This study is mainly to research Piaget's cognitive development theory and analyze its application to early childhood educa-tion.Theoratical analysis method is used. First, the source of thoughts of Piaget is explored. Second, his fundamental concepts such as schmata, assimilation, accommodation, equili-brium, cognitive structure, cognitive function, and cognitive content are analyzed. Third, the "Theory of stage (period)" including sensory-motor period, preoperation period, con-crete operation period and formal operation period is studied. Fourth, some influences from his theory are offered as follows:1).The goal of early childhood education is to cultivate creative power of children.2).Curriculum design must match the order of cognitive developmental period.3).Teaching strategies should be based entirely upon children.4).Cognitive conflict hypothesis is applied to instruction and focused on the balance of self-regulation.5).Social interaction is used for devising teaching strategies.