We have analyzed the effective constitutive parameters for a random medium containing small chiral spheres embedded in an achiral background medium by using our approach.The approach is based on an unconventional multiple scattering method by which wave scattering can be systematically treated in a medium whose dielectric particles are randomly displaced from a uniformly ordered spatial distribution.We have made clear the characteristics of the effective medium parameters by changing the volume fraction and constitutive parameters of chiral spheres.