We have performed Shubnikov-de Haas (SdH) measurements on Type II InAs/GaSb quantum wells with different InAs layer thickness. A ”blue shift” in the SdH frequency due to the suppression of the hybridized 2D electron-hole wave functions was observed. The ”blue shift” is a direct evidence for the mixing of the InAs conduction band and the GaSb valence band. The results suggest that the e-X line observed in the far-infrared cyclotron-resonance spectrum originates from the conduction-valence Landau level the mixing effect.