In general, due to the presence of different compounds in food, there is a possibility of different types of interactions between different components. One of these interactions is incompatibility between compounds, which ultimately leads to system instability due to phase separation. One of the existing methods for stabilizing such unstable aqueous systems is the use of stabilizing nanoparticles under the Pickering mechanism, which is called stabilized system resulting water-in-water emulsion. In this study, the stabilizing effect of Vicia ervilia protein nanoparticles on an unstable system containing gelatin and maltodextrin was investigated. For this purpose, Vicia ervilia protein nanoparticles were first prepared and their properties investigated. In the next step, the produced nanoparticles were used to stabilize the water in water emulsion containing gelatin and maltodextrin. Finally, additional tests were performed to investigate the structure and properties of the stable emulsion. In order to investigate the physicochemical properties of the nanoparticles, the structure and size tests were performed using scanning electron microscopy (SEM) and the particle size was estimated to be about 59.82 ± 16.47 nm. According to the contact angle test, the contact angle of the Vicia ervilia protein nanoparticles decreased with respect to the Vicia ervilia protein particles. Fourier transform infrared spectroscopy (FTIR) was performed to investigate the chemical structure of the protein nanoparticles after various treatments, including ultrasonic. X-ray diffraction (XRD) was also performed to investigate the crystallinity of the protein particles before and after the nanoparticles were processed, and the results showed the amorphous structure of these particles. Thermal Analysis (STA) were performed and indicated that the conversion process of Vicia ervilia protein to its nanoparticles had no effect on the thermal behavior of the protein and did not alter its nature. Dynamic light scattering (DLS) and zeta potential were performed to investigate the size and surface charge of the nanoparticles, as confirmed by the microscopic images of the nanoparticles, confirming the tendency of the nanoparticles to aggregation. The color measurement was performed using the Hunterlab system and showed an increase in L * and a decrease in a * and b *. In the second step, the protein nanoparticles produced were used to stabilize the water emulsion in maltodextrin and gelatin. 0.5% nanoparticles was able to stabilize the system. The drop test confirmed the presence of maltodextrin in the continuous phase of the emulsion. In order to investigate the properties of the emulsion obtained while performing rheometeric tests with the plate and cone system model, its microscopic structure was examined by confocal laser scanning microscopy (CLSM). To ensure the stability of the emulsion sample under ambient conditions, stress and thermal stability were carried out at 80 ?C and the results showed that the system under the stresses maintained its stability well. Key Words Nanoparticles, Bovine protein, Water-in-water emulsion, Phase separation, Ultrasonic treatment