To analyze the property of nuclear matter in the 16O+208Pb collision system, the internuclear potential of the fusion reaction is calculated by using the Skyrme forces associated with an extensive nuclear matter incompressibility K range in the semiclassical energy-density formalism. Comparison of the experimental fusion cross sections and those obtained by using potentials derived from different forces with various K values shows that the incompressibility of nuclear matter changes during the fusion process at different bombarding energies. The results indicate that, as the energy increases, the nuclear matter becomes more incompressible.