  We investigate the perturbative part of Seiberg's low-energy effective action
of N=2 supersymmetric Yang-Mills theory in Wess-Zumino gauge in the
conventional effective field theory technique. Using the method of constant
field approximation and restricting the effective action with at most two
derivatives and not more than four-fermion couplings, we show some features of
the low-energy effective action given by Seiberg based on $U(1)_R$ anomaly and
non-perturbative $\beta$-function arguments.
