  We study a relation between nuclear forces based on phenomenological approach
(V_ph) and nuclear effective field theory (V_EFT) from a viewpoint of
renormalization group. We find the relation between these two types of nuclear
force using Wilsonian renormalization group equation. Considering the fact that
V_EFT is defined in a certain small model space, we show that a simple contact
interaction accurately simulates short-distance physics, and that V_EFT is free
from dependence on modelling the details of the short-distance physics. Based
on our result, we discuss some features of nuclear effective field theory.
