A numerical analysis of a Helmholtz type pulse combustion burner was carried out by using the method of characteristics. Before carrying out detailed calculations, a simple acoustic model is examined, and it is revealed that a phase lag in combustion plays an important role in pulse combustion. The importance of mixing time or flame spreading time is discussed by introducing results of a model using Arrhenius' equation. In the calculations by the method of characteristics, assuming that combustion starts at a certain time after the introduction of fresh air and fuel, the constant combustion delay time model can simulate most of the important features of the burner system. The effects of a decoupling chamber are discussed, and it is shown that the volume of the chamber should be at least ten times as large as that of the combustion chamber in order to fully attain the decoupling effect.