The MBE GaAs1-xSbx/GaAs strained layer quantum well has been investigated by means of photoreflectance measurement. The energy band structure has been estimated by theoretical fitting with the experimental results. We confirmed that the variations of band structure caused by hydrostatic component of the strain mainly exist in conduction band, and that MBE GaAs1-xSbx/GaAs strained layer quantum well is a typical one of type Ⅱ. The theoretical estimation coincide well with our experimental results.