  It is of great important to study pulsar beam shapes if we are concerned with
emission theories and pulsar birth rate. Both observations and/or the inverse
Compton scattering model show that different emission components are emitted
from different heights. The relative longitude phase shifts due to different
heights of emission components and to the toroidal velocity of electron are
considered in this paper. Several possible observational features arising from
the phase shift effects are presented. The emission beams may not have circular
cross sections although the emission regions may be symmetric with respect to
the magnetic axes.
