  We investigate the degree of spin polarization of single top quarks in the
$e\gamma$ collision via the process $e^{+} \gamma \to t \bar{b} \bar{\nu_{e}}$
with center of mass energies $\sqrt{s}$=0.5, 1 and 1.5 TeV of the parental
linear $e^{+}e^{-}$ collider. Dominant spin fractions and spin asymmetries for
the various top quark spin bases are investigated. We show that $e^{+}$-beam
direction is the favorite top quark spin decomposition axis. It is found to be
comparable with the ones in $pp$ and $ep$ collisions.

High Energy Physics - Phenomenology