We investigate the entropy bound for local quantum field theory in this paper. Both the bosonic and fermionic fields confined to an asymptotically flat spacetime are examined. By imposing the non-gravitational collapse condition, we find both of them are limited by the same entropy bound $A^{3/4}$, where $A$ is the boundary area of the region where the quantum fields are contained in. The gap between this entropy bound and the holographic entropy has been verified.