Density and speed of sound of an aqueous solution of glycine and L-valine containing 1-dodecyl-3-methylimidazolium bromide, [C12mim] [Br], have been determined at T= (288.15 K to 308.15 K). From experimental density, the apparent molar volumes (Vϕ), the apparent molar volumes at infinite dilution (Vϕ0) and partial molar volume of transfer ΔVϕ0have been calculated. The values of apparent molar volumes (Vϕ) are positive for both glycine and L-valine and increase with the increase in temperature and concentration of 1-dodecyl-3-methylimidazolium bromide. On the other hand speed of sound data have been used to determine partial molar isentropic compression (Kϕ,s), partial molar isentropic compression at infinite dilution (Kϕ,s0) and partial molar isentropic compression of transfer ΔKϕ,S0. The obtained volumetric and acoustic parameters will be helpful to understand mixing effects, structural changes and other complex biological processes between head and side-chain groups of glycine or L-valine and ionic liquid [C12mim] [Br] in aqueous medium.