In this research, the effects of stress triaxiality and the Lode angle parameter on the ductile fracture behavior of ST-37 steel have been studied in detail. To investigate negative stress triaxiality conditions, uniaxial tensile and compression tests were performed on specimens with specific geometries, including dog-bone shaped specimens and notched specimens with elliptical holes. These experiments enabled the creation of negative stress triaxiality values within the range of -0.348 to -0.456. A combined approach, encompassing both experimental and numerical methods, was employed for the accurate analysis of fracture behavior. In the numerical part, the Ganjiani fracture model, considering damage parameters, was implemented through finite element simulations in Abaqus software, utilizing the VUHARD and VUSDFLD user subroutines. The comparative analysis of experimental and numerical results demonstrated a significant agreement in predicting the fracture strain. Numerical evaluations further revealed that fracture concentrates in regions with the highest plastic strain. These findings support the notion that stress triaxiality plays a crucial role in ductile fracture. Furthermore, it was observed that the trends in fracture strain variations under both positive and negative stress triaxiality are similar and consistent. This research provides deep insights into the fracture mechanisms of ST-37 steel under complex stress conditions.