Barium strontium titanate (Ba 1- x Sr x TiO 3 ) is a novel material that has significantly contributed to most electronic industries. Ba 1- x Sr x TiO 3 is synthesized by a new sol–gel method with a different composition ( x  = 0.3 to 0.6). (Ba, Sr) acetate is a source of (Ba +2 , Sr +2 ions) and titanate isopropoxide is a source of Ti +4 . The particle size of each sample was revealed by FESEM images, showing a reduction from 197 to 46 nm when the x ratio increased from 0.3 to 0.6. The X-ray diffraction revealed the phases of all the samples. Ba 0.7 Sr 0.3 TiO 3 appeared as a tetragonal phase. The remaining samples were shown to be in the cubic phase. As the concentration of Sr +2 ions rose, the major peak intensity decreased, and its angles changed. The dielectric constant was investigated for all samples. It was studied as a function of temperature and frequencies. The dielectric constant was higher for the x  = 0.3 sample than the remaining ratio. The optical constant was investigated. The energy bandgap was decreased with an increase in Sr +2 ions and transmittance, and absorbance also varied with increases in Sr +2 ions.