This study focuses on the structural and the semantic aspect of the Adverbial Group and the Postpositions in Bangla(Bengali). Bangla Adverbials and Postpositions pose significant ambiguity during syntactic analysis of different Bangla sentences. This study attempts to eliminate the ambiguity to a significant extent with the help of a set of chunking rules. The study describes these chunking rules that helps to identify and understand the function of these groups. The paper also describes the concept, origin and functional behavior of Postpositions in Bangla. Postpositions in Bangla often function as case endings that develop syntactic relationship between different syntactic units. They carry important semantic information about the relationship between the noun and the verb syntagm.