We present a calculation of the magnetic hysteresis and its area for a model continuum spin system based on three-dimensional (Φ2)2 model with O(N) symmetry in the limit N-->∞, under a time-varying magnetic field. The frequency dependence of the hysteresis area A(f ), namely, hysteresis dispersion, is investigated in detail, predicting a single-peak profile which grows upwards and shifts rightwards gradually with increasing field amplitude H0. We demonstrate that the hysteresis dispersion A(f ) over a wide range of H0 can be scaled by scaling function W(η)~τ1A(f,H0), where η=log10(fτ1) and τ1 is the unique characteristic time for the spin reverse, as long as H0 is not very small. The inverse characteristic time τ-11 shows a linear dependence on amplitude H0, supported by the well-established empirical relations for ferromagnetic ferrites and ferroelectric solids. This scaling behavior suggests that the hysteresis dispersion can be uniquely described by the characteristic time for the spin reversal once the scaling function is available.