  We discuss the helicity polarization which can be locally induced from both
vorticity and helicity charge in non-central heavy ion collisions. Helicity
charge redistribution can be generated in viscous fluid and contributes to
azimuthal asymmetry of the polarization along global angular momentum or beam
momentum. We also discuss on detecting the initial net helicity charge from
topological charge fluctuation or initial color longitudinal field by the
helicity polarization correlation of two hyperons and the helicity alignment of
vector mesons in central heavy ion collisions.
