The Sm and Nb substituted 90% of BaTiO3-10% of Li0.5Fe2.5O4 are synthesized using solid state preparation method. The X-ray diffraction, the frequency dependent of impedance, complex impedance at different temperatures, Nyquist plots at different temperatures, the variation of modulus and conductivity with high frequency region between 1 MHz and 3.2 GHz at 30 degrees C of composites were studied. The impedance of composites decreases steeply beyond 100 kHz and impedance value of 90BLF increases with increase in the concentration of Sm and Nb in BLF. The real and complex impedance changes with frequency. As temperature increases the real part of impedance of composites decreases and beyond certain frequencies, the impedance decreases sharply and merge at 10 MHz. As temperature increases the complex impedance Z ''(max) peaks shifted towards higher frequency i.e peak frequency f(max) increases with increase in temperature. The impedance curve of composites identified by exhibits single semi circle represents type of relaxation described by Debye model. The relaxation time (tau) of composites decreases with the increase in temperature. Beyond frequency 3 GHz, the modulus of composites exhibits complex behavior and the complex modulus (M '') peaks exhibits jumping behavior could be explained by Debye-type relaxation. The conductivity peak of 90BLF composites are shifted towards higher frequency with the increase in concentration of Sm and Nb in it due to the substitution of Nb and Sm in 90BLF.