  We study jet substructures of a boosted polarized top quark, which undergoes
the hadronic decay $t\to b u\bar d$, in the perturbative QCD framework,
focusing on the energy profile and the differential energy profile. These
substructures are factorized into the convolution of a hard top-quark decay
kernel with a bottom-quark jet function and a $W$-boson jet function, where the
latter is further factorized into the convolution of a hard $W$-boson decay
kernel with two light-quark jet functions. Computing the hard kernels to
leading order in QCD and including the resummation effect in the jet functions,
we show that the differential jet energy profile is a useful observable for
differentiating the helicity of a boosted hadronic top quark: a right-handed
top jet exhibits quick descent of the differential energy profile with the
inner test cone radius $r$, which is attributed to the $\mbox{V-A}$ structure
of weak interaction and the dead-cone effect associated with the $W$-boson jet.
The above helicity differentiation may help to reveal the chiral structure of
physics beyond the Standard Model at high energies.
