  The electron paramagnetic resonance is used to measure the single-ion
anisotropy of Gd3+ ions in the pyrochlore structure of (Y{1-x}Gdx)2Ti2O7. A
rather strong easy-plane type anisotropy is found. The anisotropy constant D is
comparable to the exchange integral J in the prototype Gd2Ti2O7, D~0.75J and
exceeds the dipolar energy scale. Physical implications of an easy-plane
anisotropy for a pyrochlore antiferromagnet are considered. We calculate the
magnetization curves at T=0 and discuss phase transitions in magnetic field.
