This study investigates how nanoparticle size affects the porosity and electrical properties of the perovskite oxide Barium strontium titanate Ba1-xSrxTiO3 thin film. Investigations of nanostructures and properties showed their dependence on the value of ratio x. The crystallographic features of the materials are characterized using X-ray diffraction (XRD). When the value of x increased, the XRD pattern changed from the tetragonal phase to the cubic phase. The FESEM images revealed that the particle size varied with increasing x values. The findings show that when the ion diameter changes, the crystal structure changes, which affects how stable and symmetrical the BaSrTiO3 thin films are. We calculated the film density of those samples using different methods, based on the porosity and mean film density values determined using different techniques. Electrical properties depend on the ratio of x and the annealing temperature investigated; the conductivity increased depending on the varied frequency.