Abstarct: This research focuses on the detailed investigation of the mechanical behavior of Advanced High-Strength Steels (AHSS), specifically analyzing the effect of the phase ratio of ferrite and martensite. Due to their exceptional combination of high strength and energy absorption capability, AHSS are considered a strategic choice in the automotive industry for reducing vehicle weight and enhancing safety. These characteristics result from the dual-phase structure of ferrite and martensite, where the phase ratio significantly influences the mechanical properties and fracture behavior of the steel. The primary objective of this study is to develop finite element models to analyze the effect of the martensite and ferrite phase ratio on the mechanical properties of AHSS, including yield stress and Young's modulus, using numerical simulation in Abaqus software. For this purpose, a representative volume element (RVE) consisting of approximately 1091 crystals was designed and simulated. The phase ratios studied ranged from 1:1 to 1:4, with independent grain size distributions and spatial dispersions applied for each phase. Grain orientations were determined using a random distribution function to enhance simulation accuracy. Periodic boundary conditions were employed in the uniaxial loading simulation. The representative volume was considered as a cubic element with an edge length of 8 micrometers and consisted of 64000 cubic elements. A viscoplastic model was used for modeling the crystal behavior, and the constitutive equations were coded in a VUMAT subroutine. This model was then applied in the Abaqus explicit dynamic solver. The results indicate that increasing the martensite phase percentage significantly raises the yield stress. This research demonstrates that the developed methods for constructing the finite element model of the representative volume can be used as a basis for future studies on dual-phase steels and contribute to a better understanding of the mechanical behavior of these materials.