In this project, silica nanoparticles () with a size of 15-10 nm were used for the preparation of poly (vinyl chloride) (PVC) and poly (Vinyl Alcohol) (PVA) nanocomposites NCs containing BSA. In order to prevent the accumulation of silica , the were first modified by the biocompatible BSA modifier. This process was performed in the presence of ultrasonic waves. The modified SiO 2 have been identified by the FT-IR, XRD, FE-SEM, BET, EDX, TEM, and TGA methods. In the first project, NCs of PVC was prepared using different percentages of modified (3, 6 and 9 wt%). In the second project, instead of PVC, PVA was used to prepare the NCs. NCs have been identified using FT-IR, XRD, FE-SEM, BET, UV-Vis, EDX, TEM, and TGA methods. Regarding the histogram and the natural distribution curve, the modified-BSA SiO 2 represent a uniform dispersion in NCs and according to FE-SEM images, spherical morphology modified nanoparticles were shown and according to the XRD test, observation The PVC, SiO 2 , PVA, BSA, amorphous behavior and PVA showed semi-crystalline behavior. According to the UV-Vis absorption chart, the amount of absorption increased with increasing the SiO 2 content. The mechanical and thermal properties and wettability of all nanocomposites also increased compared to pure polymer.