I will talk about the scattering operators on conformally compact Einstein manifolds based on the work of Graham and Zworski. A conformally compact Einstein manifold comes with a conformal manifold as its conformal infinity. I will show scattering operators, as spectral property of the bulk space, in many ways are related to global conformal property of the infinity. I will in particular talk about a recent joint work with Colin Guillarmou on the relation of the location of real scattering poles and the Yamabe constant of the conformal infinity.