摘要：The purposes of this study were to investigate how children`s categorization differs in object categorical hierarchy and to examine whether these aspects were different according to the children`s age of 18 months,24 months,30 months. The participants consisted of 120 young children aged 18 months,24 months,and 30 months from 31 child-care centers located in middle-income regions of Seoul and Kyonggi Province. The major findings were as follows：First,all the children from all three age groups could consistently differentiate the superordinates;however,they could not consistently differentiate basic categories. Second,24 month appears to be a critical change period in category development. Third,as the children become older,they are able to acquire more knowledge regarding categories. These results suggested that the advent of ordering,in terms of basic categories as well as superordinates which occurred around the age of 24 month,was confirmed in category development.
