Abstarct: The settlement is one of the factors that can change the conditions of dams and causes serious damage to them. Estimating the rates of these settlement play an important role in control of stability and deformation of the embankment dams during the construction and design of the body and its related structures. In the present study, the aim is studying of the settlement of Narmab dam using numerical modeling during construction and the first impounding. The Narmab dam is a homogeneous embankment dam with a height of 60 m, width of 10 m and the crest length of 807 m and reservoir volume 115 m m^3, which is built in Minudasht County. To control settlement of the fondation and body of Narmab dam, five extensometer stations were used in order to measure settlement of the fondation and body of Narmab dam which 2 different sections were used in this study. using the numerical analysis and considering the geotechnical parameters of the foundation and body of the dam, geological profile, pressure due to overburden and the level of underground water, The settlement and total deformation of the foundation and body of the dam have been modeled. Numerical modeling was performed using PLAXIS software, taking into account the step-by-step construction and in accordance with the implementation process of the dam. The results show that the data obtained from numerical modeling were in good agreement with the instrumentation data. In addition, it is observed that the dam function is appropriate in relation to the pore pressure, settlement and stresses. The maximum settlement at the end of construction occurs in the middle third of the dam height and is 1.6 m. This value is approximately 3% of the dam height, indicating that the dam behavior is acceptable. The pore water pressure created by the laxyer-by-laxyer construction of the dam disappears at each stage due to the consolidation, so that at the end of the construction phase, it can be ignored. In the long-term analysis, the maximum displacement of the dam after five years reaches 2 meters and then it remains almost constant, which indicates that the dam is safe in the long term.