The final purpose in this dissertation is to investigate and demonstrate the adjective in modern Japanese, about their morphology with their compounds. In the meanwhile, the basic concept and terminology to be related to morphology will be defined and be recorded. In this phase the conclusion to be obtained as follows: the ‘compound adjectives’ can be classed as listed below: (be depended on word-formation) (1)subject-predicate form ((N׀׀A)) (「みみどおい」、「はらぐろい」etc.) (2)object-predicate form ((N׀A)) (「ひとなつかしい」、「ひとなつかしい」etc.) (3)coordinative form (A1&A2) (「おもくるしい」、「かたくるしい」etc.) (4a)modify form I ({N/A/Mi}/A) (「しおからい」、「かびくさい」etc.) (4b)modify form II (N/A) (「なみだもろい」、「めあたらしい」etc.) (4c)modify form III (V-(i)/A) (「ききにくい」、「みづらい」etc.) (4d)modify form IV ({N/Pre}/A) (「はなはずかしい」、「てきびしい」etc.)