Abstract: By means of a single-tube set-up,the effect of jet flow exciting frequency ( f ) on refrigeration efficiency ( η ) and the influence of some factors,i.e. tube length, expansion rate, heat transfer conditions and discharging at the heat end of the tube,on optimal jet flow exciting frequency are studied experimentally in this paper.The results show that there exists a number of peak value refrigeration efficiency when the exciting frequency is increased.The variation of η due to the change of f can be over 12%.The optimal jet flow exciting frequency is significantly decreased when the tube length is increased, the expansion rate is decreased,the heat transfer condition outside of the tube is improved, or a part of heat gas is discharged at the heat end of the tube.An optimal parameters matching relationship, which can be used to predict the value of the optimal jet flow exciting frequency, is obtained.