The derivative adjectives of Korean are more a /proper` adjective than any other kinds of Korean adjectives. We can conform this point both in contemporary Korean and in various archives coming from the fifteenth century till the nineteenth century. The derivate adjectives of Korean have never functioned as a verb. By examining their historical development, we can find out how this most typical adjectives of Korean have changed throughout the period of modern Korean, and how the new adjectives were added to the inventory of the Korean adjectives during the period. In this period the intensive competition in productivity among a number of adjective-forming suffixes with similar function leaded to the disappearance of some groups of adjectives and to the appearance of new adjectives. In some cases, the new adjectives had been formed through restructuring. For instance, the derivative adjectives of `-Λh-` type had been formed through restructuring.