  In many symbiotic stars there appear broad wings around H alpha, of which the
formation mechanism proposed thus far includes a fast outflow, the inner
accretion disc motion, electron scattering and Raman scattering of Ly beta. We
adopt a Monte Carlo technique to simulate the Raman scattering of UV photons
that are converted into optical photons around H alpha forming broad wings, and
compute its polarisation. Noting that many symbiotic stars exhibit a bipolar
nebular morphology and polarisation flip in the red wing part of the Raman
scattered O {\tiny{VI}} features, we assume that the neutral scattering region
is composed of the two components. The first component is a static cylindrical
shell with finite thickness and the other component is a finite slab that is
moving away with velocity v_p = 100 km s^{-1} along the symmetry axis of the
first component. The cylindrical shell component yields polarisation in the
direction parallel to the cylinder axis. The polarisation near the line-centre
is weaker than in the far wing regions because of the large Rayleigh scattering
numbers due to the large scattering cross sections near the line centre. The
receding polar scattering component produces strong polarisation in the
direction perpendicular to the cylinder axis. When the both scattering
components coexist, the polarisation is characterised by weak parallel
polarisation near the line-centre and strong perpendicular polarisation in the
red part. We discuss the observational implications of our computation.
