Abstract: N, N Dialkyl substituted alkyl amide has been used as a extractant recently.Cheeper cost, stability, better decontamination of uranium from some fissionproducts, higher separative coefficient of uranium-thorium and less-deleteriousdegradation products make it more usefull in some extraction systems. In this work, at higher nitrate ion concentration, the extraction of uraniumand at Iower nitrate ion concentration the binary synergistic extraction of uraniumby using DIPBA and DIPBA-HPMBP respectively were investigated. At higher nitrate ion concentration, the extractive equilibrium constant of N,N-DIPBM was determined to be Logβ_(10)=-0.27. By determining the effect oftemperature on the distribution ratio, △G°, △H and △S°of the individual reactionwere evaluated as follows: △G°=-1.72kJ/mol; △H=-16.2kJ/mol; △S°=-60 J/Kmol. At pH=1.5, DIPBA and PMBP have synergistic effect. The formation ofbinary extracted complex, UO_2(PMBP)_2, DIPBA, was confirmed by the usual slopemethod. The equilibrium constant Logβ_(12)=4.51, and the effect of temperature△S°_(12)=-14.4 J/Kmol were determined.