The relative viscosities were measured for LiBr and refrence salt Bu4BBPh4, KCl in wide range composition of mixture of DMSO and water at 25oC to obtain jones-Dole b-coefficients. The b-coefficients of these electrolyes in DMSO were positive which behave as structure makers while in H2O and DMSO-H2O) mixture, the b-coefficients values are less positive showing weak structure-making effects. The values of ionic b-coefficients are suggesting that the Li+ ions is structure-maker while Br- is structure-breaking in H2O and Mix III i.e. 20% DMSO + 80% water.