FRW/CFT duality is a proposal for a holographic dual description for universe created by bubble nucleation. For (3+1) dimensional universe, the dual theory is defined on 2-sphere at the boundary of open universe. I will study correlation functions and explain essential features of FRW/CFT duality: One bulk field corresponds to a tower of CFT operators The boundary theory contains 2D gravity, and the Liouville field plays the role of time. Energy-momentum tensor has dimension 2, as required from the 2D conformal symmetry.