We propose a simple effective chiral Largrangian for the description o
f the vector and the axial-vector meson fields as well as the pious. B
y changing the form of the field-strength tensor of the vector field,
we can get a very satisfactory phenomenology with only the mass and ki
netic terms. Applying our effective model to the ratio of D-and S-wave
amplitude for a(1) --> mu pi, we obtain a consistent result with the
experiment, while the hidden-gauge nor the massive Yang-Mills schemes
does not.