In the present work, nano-silica was used in preparing LLDPE/nano-silica as an outer layer film for LLDPE reinforced nano-silica/LDPE/LLDPE multilayer film for microwavable packaging materials in future work. Thus, the objective of this work was studied the optimal of modified nano-silica loading into LLDPE film on barrier and mechanical properties. The experiments were divided into 2 main steps: surface treatment of nano-silica with vinyltriethoxysilane by ultrasonic agitation, and preparation of linear low density polyethylene film reinforced with untreated and treated nano-silica which different silica quantities are 1, 3, and 5 phr by blown film extruder. And then the surface morphology of films was examined by SEM. The properties of the film were analysis, oxygen transmission rate of film was characterized by OTR, water vapor transmission rate of film was characterized by WVTR, and tensile properties (tensile strength, % elongation and modulus) of films were examined by universal testing machine. Results indicated that the LLDPE loaded with 1 phr of nano-silica treated with vinyltriethoxysilane had better tensile strength and % elongation than at 3 and 5 phr of treated and untreated nano-silica.