QCD at photon colliders

The novel possibilities of probing the photon structure and high energy limit of quantum chromodynamics (QCD) at photon colliders are summarised. We discuss the photon structure function F2γ(x,Q2), the gluon distribution in the photon and the spin dependent structure function g1γ(x,Q2) of the photon and emphasise advantages of the photon colliders for measuring these quantities. The possibility of probing the QCD pomeron and odderon in γγ and eγ collisions is also described.