  Geometrical aspects of quantum computing are reviewed elementarily for
non-experts and/or graduate students who are interested in both Geometry and
Quantum Computation.
  In the first half we show how to treat Grassmann manifolds which are very
important examples of manifolds in Mathematics and Physics. Some of their
applications to Quantum Computation and its efficiency problems are shown in
the second half. An interesting current topic of Holonomic Quantum Computation
is also covered.
  In the Appendix some related advanced topics are discussed.
