Objective: Children with intellectual disabilities (ID) have learning and educational difficulties because of variant linguistic disorders such as phonological, morphological, lexical and syntactical. This research concentrates on the study and description of some syntactic characteristics in students with ID. These syntactic features include third person plural verbs, object marker (-ra), simple past tense verbs, personal pronoun, plural marker (ha-), prepositions, negative verbs, simple present tense, linking verbs, and subordination structures. Method: seventy nine children were randomly selected from 700 students having ID in Tehran exceptional schools at 1382-3 years. The sample was made by multi-stage sampling. The apparatus used in this research was Test of Language Development –3 (TOLD-3) (The Persian version). Results: Data analysis revealed which syntactic features are difficult and which ones are simple for production and perception for this group of students. Conclusion: These results could be used in developing and improving the educational and rehabilitation programs and curriculums for children with ID.