The purposes of this study are to investigate the relationship between the Piaget s cognitive developmental theory and the practical course subject in elementary school which have the characteristics of skillful subject and living subject, and to discriminate the suitability of contents of the practical course subject for the childrens level of cognitive development. This work could serve the theoretical background that the practical course subject presents practical experiences which lead the development of logicomathematical thinking abilities. The results of the content analysis shows that create activities develop the logicomathematical thinking abilities such as projective geometry, topology geometry, area conservation, length & distance conservation, and volume & mass conservation. And the most contents of the practical course subject are suitable for the childrens level of cognitive development.