In this work¡Awe studied the strain effects on heavy hole (hh) and light hole (lh) bands of Zn1-xMnxSe/GaAs by photoreflectance (PR) spectroscopy . The Zn1-xMnxSe epilayers were grown on GaAs substrates by the MBE technique . There is a biaxial compressive strain exist in the epilayer, due to the different lattice constants between epilayers and substrates .The biaxial strain will shift hh and lh bands and lift the hh-lh degeneracy. In our experiment ,we found that the splitting of the hh and lh transition energies is almost lineally proportional to the Mn ion concentrations. It can be ascribed to the strain in the epilayer . We have also measured the PR of Zn0.96Mn0.04Se/GaAs at various temperatures , and analyzed the transition energy of different temperatures in terms of Varshni relation.