Studies have shown that in Persian, no significant research has been done on size adjectives. In this paper, near-synonymy relationship of ‘ ‘ vasiʔ , pahnâ var, bozorg’ ’ size adjectives and their inflectional forms have been studied according to Behavioral Profile approach of Divjack and Gries (2006) and the data of Hamshahri 2 corpus (Alahmad and et. al, 2009). In this research, initially all lexical and inflectional forms of size adjectives were identified and then evaluated according to morphological, syntactic and semantic ID-tags. The results indicated that based on hierarchical analysis, the groups of “ vasiʔ tarin, bozorgtarin” , “ vasiʔ , bozorg’ ’ , “ pahnâ vartar, bozorgtar’ ’ , “ vasiʔ tari, bozorgtari’ ’ , “ vasiʔ i, bozorgi’ ’ have near-synonymy relationship with each other. In addition, there is a similar distribution between the members of the group of “ pahnâ var, pahnâ vartarin” due to the existence of identical bases. Also, there is a near-synonymy relationship between the lexical forms of “ pahnâ vari” with “ vasiʔ i, bozorgi” and “ vasiʔ tar” with “ pahnâ vartar, bozorgtar” .