  We have shown an example of semiclassical transition in $\phi^{4}$ theory
with positive coupling constant. This process can be described by the classical
$O(4)$-invariant solution, considered on a contour in the complex time plane.
The transition is technically analogous to the one-instanton transition in the
electroweak model. It is suppressed by the factor $\exp(-2S_{0})$, where
$S_{0}$ is Lipatov instanton action. This process describes a semiclassical
transition between two coherent states with much smaller number of particles in
the initial state than in the final state. Therefore, it could be relevant to
the problem of calculation of amplitudes for multiparticle production in
$\phi^4$-type models.
