EPR studies of Mn2+ ions in the Pb3P2O8 crystal are presented. Peculia
rities of EPR spectra at a transition from the low to high-temperature
phase are reported. Several degrees above the phase transition temper
ature the forbidden lines are observed for a magnetic field parallel t
o the threefold axis of the crystal. It is shown that these lines coul
d be the evidence of microdomains which the ''z'' axis is deviated by
a few degree from the threefold axis.