Abstract: Numerical P systems are a class of distributed and parallel computing systems, inspired from the structure of eukaryotic cells and the idea of income allocation in economics. It has been proven that numerical P systems and their variants are Turing universal for number generating/accepting devices. However, universality of numerical P systems as function computing devices has not been established. Aiming at enzymatic numerical P systems, this paper discusses their universality as function computing devices. Two small universal function computing devices of enzymatic numerical P systems working in two modes are obtained respectively.