  We present a self-organized stochastic model for the dynamics of a single
flux line in random media. The dynamics for the flux line in the longitudinal
and the transversal direction to an averaged moving direction are coupled to
each other. The roughness exponents of the flux line are measured for each
direction, which are close to $\alpha_{\parallel}\approx 0.63$ for the
longitudinal and $\alpha_{\perp}\approx 0.5$ for the transversal direction,
respectively. The dynamic exponents are obtained as $z\approx 1$ for both
directions. We discuss the classification of universality for the stochastic
model.
