The effect of plasma treatment on the chemical compositions, morphologies, and energies of the polyimide (PI) surfaces is studied with attenuated total reflection infrared spectroscopy (ATR), contact angle measurement, and atomic force microscopy (AFM). PI studied includes Dupont H and E films. The surface energies of all three PI increase after plasma treatment and respond similarly under different plasmas. However, the ATR spectra confirm that the generated functional groups on the surfaces of PI’s are different. The surface morphologies after plasma are also different. The type of plasma also affects the extents of changes of surface functional groups and morphologies.