  In a framework of intranuclear cascade (INC) type calculation, we study a
momentum spectrum in reactions \KK at a beam momentum of 1.65 GeV/c. INC model
calculations are compared with the relativistic impulse approximation (RIA)
calculations to perform the detailed study of the reaction mechanism. We find
that the INC model can reproduce the experimental data on various targets.
Especially, in the low-momentum region, the forward-angle cross sections of the
$(K^-,K^+)$ reaction on from light to heavy targets are consistently explained
with the two-step strangeness exchange and production processes with various
intermediate mesons, and $\phi$, $a_0$ and $f_0$ productions and their decay
into $K^+K^-$. In the two-step processes, inclusion of meson and hyperon
resonances is found to be essential.
