The main purpose of this study is to explain the word order of topicalized constituents in non-pro.making persian topicalization based on Functional Discourse Grammar. Since this grammar does not believe in concepts such as movement, we will also seek to explain this process in base-generated procedures. Therefore, in this study, in order to achieve the above goals, the method of mapping the linguistic elements of sentences containing non-pro.making Persian topicalized constituents in morphosyntactic templates in four absolute initial, second, medial and final positions and infinite relative ones presented in Functional Discourse Grammar was considered. This study is based on a descriptive-analytical method and the examples are taken from selected samples of Persian speech and written texts, which after introducing the mechanisms of this grammar,have been analyzed based on the principles of this theory. The method of determining the order of constituents used in the present study is the dynamic method of FDG that is inspired by the method of determining the word order of Greenberg. In this approach instead of three categories of subject, object and verb, respectively, the concepts of actor, undergoer and predicate, determine the word order of the languages of the world. The results indicate that in marked constituents such as topicalization, considering the communicative intention of the speaker, various elements including ,thematic and non-thematic elements and even predicates can be topicalized and on the other hand, considering that, based on the principles of this grammar, the topicalized constituent in the interpersonal level is given priority in entering morphosyntactic templates, so the topicalization process is not the result of movement, but the topicalized element is produced in base-generated procedures in the same position. The results also show that Functional Discourse Grammar is an appropriate and efficient method by referring to the three principles of iconicity, domain integrity and functional stability in determining the constituent arrangement of sentences containing non-pro.making Persian topicalization.