بررسی ساخت اسم و صفت مرکب در آبان یشت، مهر یشت و تیشتر یشت اوستا

abstract compound is a word-formation process that are made two free morpheme (independent) and forms a new word with a new meaning that consists of meaning of both two component of compound. avestan language is one of the ancient iranian languages that is one of the indo-iranian languages. indo-iranian languages is one branch of indo-european languages. structure of compound noun and adjective in avestan language is like as sanskrit language and other indo-european languages. avestan compound noun and adjective are classified into different types according to relationship between compound components and referent compound word. paying attention to this classification is important for translation of avestan lexicons. in this study, compound noun and adjective are studied in three texts: ?b?n ya?t, mihr ya?t and t??tar ya?t. at first, we have divided compound words into three groups of endocentric, exocentric and coordinate. the types of these compounds are studied on the basis of model of sanskrit and avestan grammar. for example avestan endocentric compound has different types like as dependent compound, descriptive compound, determinative compound and numeral compound. then, we classified every one of these compounds on the basis of any component, for example: substantive+ substantive ?substantive. key words: substantive, adjective, compound, ya?t, avesta