  We present a calculation of full one-loop radiative corrections, including
the constant term, to the asymmetry parameter of polarised neutron beta decay.
This gives the radiative correction to the axial coupling constant $g_A$
extracted from the beta asymmetry so that it ties to $g_A$ that appears in
neutron decay lifetime in a consistent renormalisation scheme. We find that the
ratio of axial-vector to vector couplings determined from the beta asymmetry,
after taking account of the outer radiative correction, is related to the bare
value as $G_A/G_V=1.0012 G_A^0/G_V^0$.
