  For an oriented surface of genus g with b boundary components, we construct a
rational map from a subset of C^{6g-6+3b} onto an open algebraic subset of the
PSL(2,C)-character variety as an analogue of the Fenchel-Nielsen coordinates.
After taking the quotient by an action of a finite group, we obtain a
parametrization of a subset of the PSL(2,C)-character variety, and similarly
for the SL(2,C)-character variety. We can systematically calculate a set of
matrix generators by rational functions of the parameters. We give
transformation formulae under elementary moves of pants decompositions.
