  Since Weinberg's proposal two decades ago, chiral effective field theory in
the NN sector has been developed and applied up to order $O((Q/M_{hi})^4)$. In
principle it could provide a model-independent description of nuclear force
from QCD. However, in spite of its huge success, some open issues such as the
renormalization group invariance and power counting, still remain to be solved.
In this talk we refine the chiral effective field theory approach to the NN
system based on a renormalization group analysis. Our results show that a truly
model-independent description of NN system can be obtained by a new power
counting which treats the subleading order corrections perturbatively.
