Abstract: In order to investigate the effect of injector on pressure oscillation propagation from liquid rocket engine combustion chamber to pipe-line,the process of pressure oscillation propagation from combustion chamber to pipe-line was theoretically researched in this paper;and the transfer function was also deduced.The dynamic characteristic of pipe-line linked with various injectors was discussed.The influences of pipe-line length,combustion chamber pressure,injector type and configuration on pressure oscillation propagation process were calculated,the influence rule of injector and operating condition parameters on propagation process was gained finally.