  Recent works show that the original Kobayashi-Maskawa (KM) form of fermion
mixing matrix exhibits some advantages, especially when discussing problems
such as unitarity boomerangs and maximal CP violation hypothesis. Therefore,
the KM form of fermion mixing matrix is systematically studied in this paper.
Starting with a general triminimal expansion of the KM matrix, we discuss the
triminimal and Wolfenstein-like parametrizations with different basis matrices
in detail. The quark-lepton complementarity relations play an important role in
our discussions on describing quark mixing and lepton mixing in a unified way.
