  In a realistic effective one-family extended technicolor(ETC) model without
exact custodial symmetry, we calculate the one-loop corrections to the
Z-b-(anti-b) and Z-tau-(anti-tau)vertices from the sideways and diagonal ETC
bosons exchange. The result shows that both the Z-->b+anti-b partial width (and
the branching ratio) and the tau polarization asymmetry parameter A_tau are
enhanced by the corrections and are in agreement with the present experimental
data.
