  In order to test systematic of the Amati relation, the 24 long-duration GRBs
with firmly determined $E_{\gamma,\mathrm{iso}}$ and $E_{\mathrm p}$ are
separated into two sub-groups according to B-band luminosity of their host
galaxies. The Amati relations in the two subgroups are found to be in agreement
with each other within uncertainties. Taking into account of the well
established luminosity - metallicity relation of galaxies, no strong evolution
of the Amati relation with GRB's environment metallicity is implied in this
study.
