  The large abundance ratio of $^{44}Ti/^{56}Ni$ in Cas A is puzzling. In fact,
the ratio seems to be larger than the theoretical constraint derived by Woosley
& Hoffman (1991). However, this constraint is obtained on the assumption that
the explosion is spherically symmetric, whereas Cas A is famous for the
asymmetric form of the remnant. Recently, Nagataki et al. (1997) calculated the
explosive nucleosynthesis of axisymmetrically deformed collapse-driven
supernova. They reported that the ratio of $^{44}Ti/^{56}Ni$ was enhanced by
the stronger alpha-rich freezeout in the polar region. In this paper, we apply
these results to Cas A and examine whether this effect can explain the large
amount of $^{44}Ti$ and the large ratio of $^{44}Ti/^{56}Ni$. We demonstrate
that the conventional spherically symmetric explosion model can not explain the
$^{44}$Ti mass produced in Cas A if its lifetime is shorter than $\sim$ 80
years and the intervening space is transparent to the gamma-ray line from the
decay of $^{44}$Ti. On the other hand, we show the axisymmetric explosion
models can solve the problem. We expect the same effect from a three
dimensionally asymmetric explosion, since the stronger alpha-rich freezeout
will also occur in that case in the region where the larger energy is
deposited.
