The major focus of this research is on the differential disruption of language abilities subsequent to brain damages as they relate to site and size of lesion, especially left hemisphere lesions which disrupt the production and processing of "Nouns" vs. "Verbs" as two functionally different lexical categories. Several clinical as well as experimental studies reported on different language have shown that nouns and verbs can be independently disrupted due to brain damage. A prevalent impairment in naming actions (Producing verbs) is reported in non-fluent aphasic patients, with lesions involving left frontal lobe, whereas a selective in naming objects (Producing nouns) has been observed in amnesic patients, with lesions involving the temporal lobe and the temporal lobe and the posterior association aresas. This research is a theoretical and fundamental based on descriptive and analytical method. The aphasic data in this research were obtained by assessing each patient&aposs aphasic symptoms using a standard Persian aphasia test (Paradis, Nilipoure, Paribakht, 1989) as well as post-test analysis of each patient&apos connected descriptive speech. The subjects were selected form among aphasics who referred to speech therapy centers in Tehran during a pe5iod of one year since autumn 1999. The subjects selected in the study were a homogenous group with left hemisphere lesions due to CVA. They were educated adult right handed. Speakers of Persian without any risk factor such as nicotine, alcohol or any addiction and diabetes with no gross depression or anxiety problems or face and oral paralysis and hemiaopsia. The subjects in this study comprised to adults ranging between 33 and 76 years of age. The results indicated that there are significant correlation between: 1) The production of nouns and left hemisphere lesion. 2) The production of verbs and left hemisphere lesion. 3) Brain lesion and language deficits. 4) The site of lesion and language abilities. Although the data are limited and the generalization of the study has certain restrictions, the present data indicate some specific and reliable avidence on the selective impairment of nouns and verbs due to different lesions in the left hemisphere.