  We consider the defocusing, energy subcritical wave equation $\partial_t^2 u
- \Delta u = -|u|^{p-1} u$ in 4 to 6 dimensional spaces with radial initial
data. We define $w=r^{(d-1)/2} u$, reduce the equation above to one-dimensional
equation of $w$ and apply method of characteristic lines. This gives scattering
of solutions outside any given light cone as long as the energy is finite. The
scattering in the whole space can also be proved if we assume the energy decays
at a certain rate as $x\rightarrow +\infty$. This generalize the 3-dimensional
results in Shen[27] to higher dimensions.
