  Holographic principle states that the maximum entropy of a system is its
boundary area in Planck units. However, such a holographic entropy cannot be
realized by the conventional quantum field theory. We need a new microscopic
theory which naturally possesses all the holographic degrees of freedom. In
this paper, we provide some preliminary thoughts on how to construct a theory
with holographic degrees of freedom. It may shed light on the understanding of
quantum properties of gravity and the early stage of the universe.
