High resolution Fourier transform spectra, recorded between 30 and 460 cm −1 , have been used for an extensive analysis of the (n,τ)=(0,3)←(n',τ')=(0,1), (0,1)←(0,3) and (1,1)←(0,3) torsion-rotation bands of H 2 O 2 . Then, using a Hamiltonian which takes explicitly into account the strong |ΔK a |=2 interaction between the rotational levels of the (n,τ)=(0,1) and (1,1) torsional states, as well as the |ΔK a |=2 interaction between the (n,τ)=(1,1) and (2,1) rotational levels, it has been possible to reproduce very satisfactorily the experimental rotational levels of the (n,τ)=(0,1) and (1,1) torsional states and a precise set of torsional energies and rotational and coupling constants has been derived. In the same way, to fit the (n,τ)=(0,3) experimental energy levels we have used a Hamiltonian taking into account the |ΔK a |=2 interaction between the rotational levels of the (n,τ)=(0,3) and (1,3) torsional states, and this calculation has also provided a precise set of torsional energies, rotational and coupling constants for the (n,τ)=(0,3) and (1,3) torsional states Enregistrement, entre 30 et 460 cm −1 , des spectres par transformee de Fourier pour l'analyse systematique des bandes de torsion-rotation (n,τ)=(0,3)←(n',τ')=(0,1),(0,1)←(0,3) et (1,1)←(0,3) de H 2 O 2 . Emploi d'un hamiltonien qui traite explicitement la forte interaction de type |ΔK a |=2 entre niveaux rotationnels des etats de torsion (n,τ)=(0,1) et (1,1) et l'interaction en |ΔK a |=2 entre niveaux de (n,τ)=(1,1) et (2,1), pour reproduire les niveaux observes des etats de torsion (n,τ)=(0,1) et (1,1) et pour donner les energies de torsion, les constantes de rotation et de couplage