Excess molar volumes V-m(E) and kinematic viscosities v have been measured as a function of composition for binary mixtures of dipropylene glycol monobutyl ether and dipropylene glycol tert-butyl ether with 2-pyrrolidinone, N-methyl-2 -pyrrolidinone, N,N-dimethylformamide, and N,N-dimethylacetamide at 298.15 K. In all mixtures, the excess molar volumes are negative across the entire composition range. From the experimental data, the deviation in dynamic viscosity η from &USigma;χ iη i had been calculated. Both excess molar volumes and viscosity deviations are fit to a Redlich- Kister-type polynomial equation to estimate the binary coefficient and standard errors. The experimental and calculated quantities were used to analyze the mixing behavior of the components. Equations such as Heric′ s, Auslaender′ s, and McAllister′ s four-body interaction model were used to correlate the kinematic viscosities.