We demonstrate that certain domain structures can be created both in ferro-
and antiferro-magnetic spinor condensates if the initial phase is spatially
modulated. Meanwhile, spin dynamics of the condensate with modulated phases
exhibits exotic features in comparison with those of a condensate with a
uniform phase. We expect that these phenomena could be observed experimentally
using a phase-imprinting method.Comment: 5 pages, 5 figures, to appear in Phys. Rev.