Aim\ To study the effect of the foaming technology to the combustion properties of the caseless ammunition. Methods\ The \%p-t\% curves of the caseless ammunition of the different foaming technology had been measured by the closed bomb test and analysed. Results\ It is found that the foaming technology affected the relative quickness(d\%p\%/d\%t\%)and ignition property. Conclusion\ The study proved that the foaming was an effective way to improve the combustion properties of the caseless ammunition.