Abstract: Natural rubber (NR), a renewable resource, is significantly used in gloves, condoms and so on. However, NR film products have some weaknesses, such as poor solvent resistance, low tensile strength and allergic effect, which limite their applications. A high-performance thin film was prepared by blending NR with functionalized silicone-acrylate emulsion. Such emulsion possesses the better ability of film formation and weather fastness of polyacrylate, as well as the excellent heat resistance and water tolerance of polysiloxane. Additionally, O-carboxymethyl chitosan (OSC) was used as an emulsifier, which improves the biocompatibility and degradability. Cross-linkable poly (butyl acrylate-co-styrene-co-3-methacryloxypropyltris-trimethylsiloxy-silane) (PBSC) was synthesized by emulsion polymerization, and the component was confirmed by Fourier transform infrared (FT-IR) spectrograph. NR/PBSC composites were prepared by polymer blending, and their properties were studied by scanning electron microscopy (SEM), mechanic analysis, thermos-gravimetry (TG) and differential scanning calorimetry (DSC) tests. The results revealed that the holes on film surface and inside the film reduced significantly, suggesting the enhancement of compatibility between NR phase and polymer phase. The effect of 3-methacryloxypropyltris-trimethyl siloxy-silane (C1757) mass fraction and loading of copolymer on mechanical properties of NR was investigated. As the film was formed, PBSC chains were entangled with NR and significant physical crosslinking points were developed. As a result, the maximum tensile strength was achieved at the C1757 mass fraction of 12% and copolymer additive amount of 12%. Besides, cross-linked PBSC particles produced large amounts of Si-O-Si bonds with higher bonding energy, leading to the superior thermal decomposition resistance. The characteristic temperatures, T₀, T_p and T_f were increased by 12.9℃, 3.7℃ and 11.5℃, respectively, when the mass fraction of PBSC (w(C1757) was 12%) reached 12%. Meanwhile, the solvent resistance and surface hydrophobicity of NR/PBSC films were also improved and protein spillage dropped (less than 110 μg/g).