A three-dimensional Langevin equation with covariant form is applied to des
cribe the asymmetric nuclear fission. The calculations for kinetic energy a
nd mass distribution of fission-fragments are performed in terms of the {c,
h, alpha} parameterization, and the descent process of the fissioning nucl
eus from the saddle point to the scission point is simulated numerically. T
he dependence of the model on the choices for two types of nuclear dissipat
ion such as two-body viscosity and one-body dissipation, as well as the sci
ssion configurations of nuclear system with finite neck is investigated.