The inverse gas chromatography method was used for the investigation of the partition and diffusion coefficients of polyetherimide with NMP, DMSO, acetic acid, propionic acids, THF, and ethanol over a range of temperature from 230-355oC. The weight fraction infinite dilution activity coefficients for the solvents, the Flory-Huggins interaction parameters, and the solubility parameters of the polymers are reported.