  For the first time, the A- dependence of the production of $K^0$, $\Lambda$
and, for comparison, $\pi^-$ mesons is investigated in neutrinonuclear
reactions, using the data obtained with SKAT bubble chamber. An exponential
parametrization ($\sim A^{\beta}$) of the particle yields results in
${\beta}_{V^0} = 0.20 \pm 0.05$ for $V^0$ particles (combined $K^0$ and
$\Lambda$), while for $\pi^-$ mesons the A- dependence is much weaker,
${\beta}_{\pi^-} = 0.068 \pm 0.007$. A nuclear enhancement of the ratio
$K^0/\pi^-$ is found; this ratio increases from $0.055 \pm 0.013$ for $\nu N$-
interactions up to $0.070 \pm 0.011$ at $A \approx 21$ and $0.099 \pm 0.011$ at
$A \approx 45$. It is observed, that the multiplicity rise of $V^0$'s occures
predominantely in the backward hemisphere of the hadronic c.m.s. It is shown,
that the A- dependence of the nuclear enhancement of the ${\Lambda}^0$ and
$\pi^-$ yields can be reproduced in the framework of a model, incorporating the
secondary intranuclear interactions of pions originating from the primary $\nu
N$- interactions, while only (29$\pm$9)% of that for $K^0$ at $A \approx 45$
can be attributed to intranuclear interactions.
