Abstract: It presents results obtained in an ongoing project at BUAA,stemming from the need to develop more ratinoal design methods.It discusses the effect of parameters of main elements of pulse combustors,including combustor chamber,tail pipe,injector and reactant supply system upon its performance,in the aspect of satisfying Rayleigh's criterion,the basical law of pulsating combustion.It was found that,a limit of minimum length of the tail pipe exists for a certain pulse combustor to keep an indispensable acoustic impedance.The characteristic and geometry of the reactant supply system and injector are very critical.It is proposed that an engineering design approach could be developed based on a velocity similarity concept.A series of pulse heaters rating 10 kW~300 kW were developed successfully using this concept.