We investigate some properties of solutions of the Degasperis–Procesi equation, which is an approximation to the incompressible Euler equation in shallow water theory. Sufficient conditions for wave breaking are found both on an infinite line and in a periodic domain by the method of characteristics. Moreover, we show that the solution enjoys the same decay property as the initial data. Finally, the weak and strong limits, respectively, of the solution as the dispersive parameter goes to zero are investigated.