In this paper, the liquid-drop model with three parameters is used to describe symmetric or asymmetric fission process. The analytical expression of the effective moment of inertia is given. The inertial and frictional tensors of nucleus are evaluated by the Werner-Wheeler method. Based on a standard liquid-drop model, the Coulomb energy and surface energy are accurately calculated. The scission point of the fissioning nucleus is defined by energy criteria. The salient features of the dynamical coefficients are discussed.