Reinforced concrete grouped silos-commonly employed in the industry to store granular materials- also needs to be designed in earthquake-prone areas. Silos experience a higher rate of structural failures than the majority of other types of construction. And one of the main causes of silo failure is the dynamic overpressures caused by stored materials under seismic loads. However, the principles determining loads on such structures and requirements for their structural analysis are not precisely specified in relevant codes of design. Instead of emphasizing grouped silos that interact strongly, the present dynamic design only concentrates on a single silo which can lead to unrealistic solutions for grouped silos. Therefore, it is necessary to determine the seismic behavior of grouped silos more accurately. This paper aims to investigate the seismic behavior of RC on-ground grouped silos compared to single ones by using a numerical model because of its adaptability, which allows for the analysis of a wide range of silo problems. In this context, a three-dimensional finite element model, that considered the interaction between stored material and silo wall as well as the continuity of the silo walls, was performed using ANSYS software. Two different aspect ratios and three different internal loading cases were taken into account for the parametric study to demonstrate their influences on dynamic overpressures and equivalent base shear forces in RC-grouped silos. It is concluded that designing the on-ground slender grouped silos with a high aspect ratio as individual single silos is unreasonable and may produce very low values for the base shear force.