This paper presents influence of ultrasound-assisted method on structure, tolerance factor, density and Electron spin resonance studies of SrBaFexMo2-xO6 (x = 1.0, 1.1, 1.3 and 1.4) (SBFMO) double perovskite. SrBaFexMo2-xO6 double perovskite was synthesized by sonochemical procedure at low temperature (9500C) under Ar/ H2 atmosphere. X-ray diffraction studies revealed a single phase with a cubic crystal structure for all the samples. The existence of all elements (Sr, Ba, Fe, Mo, O) contamination-free in the required percentage in SBFMO compound has been analyzed by Energy Dispersive X-ray Spectroscopy (EDS). Goldschmidt Tolerance factor 't' has been used to quantitatively predict the stability 1 and closeness of A2BxB12-xO6. Density measurements for all samples of SrBaFexMo2-xO6 (x = 1.0, 1.1, 1.3 and 1.4) were done both theoretically and experimentally. Electron Spin Resonance (ESR) spectra of SrBaFexMo2-xO6 (x = 1.0, 1.1, 1.3 and 1.4) were studied to determine the iron state in the compound by varying magnetic field at a constant frequency (X-Band).