  The causality properties of space-time models with traversable wormholes are
considered. It is shown that relativity principle cannot be applied to the
motion of the wormhole's mouths in the outer space and the dynamical wormhole
transformation into the time machine is impossible. The examples of both causal
and noncausal space-time models with traversable wormholes are also considered.
Some properties of space-time models with causality violation are briefly
discussed.
