Abstract: The radial basis function network (RBFN) is studied and its neurocomputing performance is contrasted with fuzzy logic operation. It is concluded by theoretical analysis that the RBFN holds fuzzy operation nature, and the RBFN is a kind of neuro-fuzzy systems in a sense. To illustrate the analysed conclusion the fuzzy clustering problem of butterflies is examined with the RBFN. As it turns out that the examined results verify the theoretical conclusion.