A Helmholtz-type pulse combustion system was designed. The capacity of the combustion system is 25 kW and liquefied petroleum gas is used as a fuel with the features of flapper valves and frequency rang from 60 to 105 Hz. A pressure inside the combustion chamber of pulse combustor is monitored by a pressure transducer and the variation of the pressure amplitude and frequency with the length of tail tube changing are discussed. The heat transfer coefficients of oscillating flow produced by pulse combustor and nonoscillating flow are obtained. It indicates that the heat transfer coefficient of oscillating flow is 2.5 to 3.2 times greater than that of nonoscillating flow.