- Both the nucleon-nucleon inelastic and the kaon-production cross sections in dense nuclear matter are evaluated in the one-pion exchange model. The medium effect is included by using the dressed pion propagator determined in the delta-hole model. Compared with the cross sections in free space, it is found that the nucleon-nucleon inelastic cross section is substantially enhanced at high nuclear-matter densities while the kaon-production cross section is only moderately increased. In the normal Vlasov-Uehling-Uhlenbeck model for heavy-ion collisions the total kaon yield is seen to be sensitive to the nuclear equation of state. 1989.