The present study is to investigate the role of lithology and tectonics in the longitudinal profile of the Agh Chay River. Given that tectonic studies have not been conducted in the Agh Chay River basin and tectonics is one of the factors affecting the longitudinal profile, it is absolutely necessary to conduct a study on tectonic activity in the basin. The area in question is located at longitude "10'10°44" to "50'57°44" East and latitude "0'3°39" to "40'40°38" North. In terms of topography, the area in question has two units: mountains and plains, which are drained by the Agh Chay River. Geologically, there is diversity in the basin, most of which are mainly related to ophiolite complexes and metamorphic rocks of unknown age, which have high resistance. To achieve the research objectives, morphometric indices have been used, including: river longitudinal slope index (SL), drainage basin shape ratio (BS), drainage basin asymmetry index (AF), standardized SL index (SL/K), hypsometric curve, hypsometric integral (Hi), surface density index of watercourses (P), and valley floor width to height ratio index (V_f). In general, the results of the index measurements show that the region is relatively tectonically active and the amount of activity varies in different parts of the region; meaning that according to the results of all indices, it is almost more active in the downstream part than in other parts. Finally, after examining the morphometric indices in the region, the lat index was also used to estimate the total tectonic activity. Overall, the region can be considered relatively active in terms of tectonic activity. Also, by using the SL index and the intersection of geological formations with the river profile, the effect of lithology on the longitudinal profile of the river is clear.