In this work, Bi1-xLaxFeO3 (BLFO) and Bi0.9-YLa0.1BaYFeO3 (BLBaFO) nanoparticles were synthesized by different amounts of barium and lanthanum in ferrite bismuth (x = 0, 0.05, 0.1, 0.15, Y = 0.05, 0.1) using the hydrothermal method in the presence of crosin as a natural surface activator based on sugar. Then, structural, magnetic, size and morphological properties of synthetic nanoparticles were investigated using Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), Transmission Electron Microscope (TEM), Scanning Electron Microscope (FE-SEM), Dynamic Light Scattering (DLS) and Vibrating Sample Magnetometer (VSM). XRD showed that by increasing the concentration of lanthanum and barium perforated in ferrite bismuth, a phase change occurred from rhombohedral structure to tetragonal. The presence of tensile vibrations in the zone of 400-600 cm-1 associated with Fe-O, Bi-O, and Ba-O bonds in the FT-IR confirmed the production of these nanoparticles. TEM images for Bi0.9La0.1FeO3 nanoparticles showed the particle size of about 25 nm and uniformity in morphology, and the existence of approximately spherical structures. The optimum magnetic performance was observed when the amount of lanthanum inserted in bismuth ferrite in the presence of surface activator crocin was x = 0.1 in stoichiometry. Also, the effect of various natural surface activators based on sugar such as saponin, Triton CG-100, crocin and N-acetyl-beta-D-glucoside were investigated by DLS.