A generalized spherical harmonics expanded orientation distribution function (ODF) has been used to study the orientation of SWNTs. A relationship between the second- and fourth-order SWNT orientation parameters and the Raman scattering intensity and depolarization ratio has been established. Only by determining the VV and VH intensities at 0degrees and 90degrees to the orientation direction, the second- and fourth-order SWNT orientation parameters can be determined. From the second- and fourth-order orientation parameters, orientation distribution function can be constructed using the maximum entropy formalism. (C) 2003 Elsevier B.V. All rights reserved.