The Hall factor in a two-dimensional device with indirect conduction valleys is calculated for several growth on various strain conditions. In the [001] or [111] growth direction, the two-dimensional constant energy surfaces of occupied valleys are shown to be isotropic ally distributed. However, in the [110] growth direction, the distribution of occupied valleys on the plane is not isotropic. This fact is the reason for the anisotropic Hall factor on the sample plane.

The Hall factor in a quantum well structure with X or L-type indirect conduction valleys is calculated for various strain conditions. The two-dimentsional constant energy of occupied valleys are proven to be identical. As a result the Hall factor depends on the direction of occupied valleys to the growth direction, regardless of the number of occupied valleys. This work is widely applicable to the two-dimensional structure with indirect conduction minima for any growth direction and under different strain conditions.