The purpose of this study was to find the strategy effective to the formation of “Animal Concept” in children: i. e.bushy feet being index for carnivorous animals, tough feet for the hervibores, through the constructive method.In Exp.1, the functional meaning of the animals'feet for their lives was emphasized in focus instances without the rule being stated.In result, the denotative learning was enough, but not connotative.And the functional meaning was expanded to the unlearned form in children, but its effect was found only in the carnivorous types.So, the instructions of Exp.2were improved as follows,(1) the rules were verbalized,(2) the “application exercises” of the rule were applied, and so on.Such improvements were seen effective to the acquisition of the connotation and the denotation of the rule.It was suggested that learning the functional meaning was not likely to contribute to the denotative extension of the rule, and the application exercises could be proved important also for a sufficient acquisition of the rule.