All languages in the world use different mechanisms to create new words. Derivation and compounding are two morphological processes whose main function is the formation of new word-forms. In Persian, derivation is one of the dynamic and widely used processes of word formation. In the realm of derivation, Persian language has many prefixes and suffixes that can be attached to existing words in order to create new words. One of these suffixes is "-ār" which is considered as one of the semi-productive suffixes of Persian language; however, the observations reveal that it has become a productive suffix in today's Persian. The main purpose of this research is to study the derivational construction [x-ār] in Persian within the framework of Construction Morphology (CM). It makes use of the notion of ‘construction’, which is defined as a pairing of form and meaning, to describe the properties of complex words. Therefore, on the basis of a construction-based approach and regarding a descriptive-analytic method, the authors try to represent the systematically semantic varieties of "-ār", possible schemas and subschemas and also the hierarchical structures, based on which, [x-ar] construction has been achieved. The data analyzed in this study has been gathered from three sources: Reverse Dictionary (Zansu) (Keshani, 1993), Persian Linguistic Database (PLDB) and FarsNet. Then, the extracted words have been examined in Farhang-e Bozorg-e Sokhan (Anvari, 2002) and obsolete items have been excluded. The findings of the research show that “-ār” has seven different meanings (functions) and thus we can consider it as a polysemous suffix. Its polysemy is not explainable at the level of words, but at the level of abstract schemas; hence, it is called “constructional polysemy”. The results of this study indicate that "entity with relation R to SEM" is the prototypical meaning of [x-ār] which is the most abstract correlation among meaning and form in Persian language.