The present invention relates to the technical field of radio communications, and specifically relates to a method, device, and system for transmitting a reference signal, for use in solving the problem in the prior art that vertical-dimension channel estimation cannot be supported and thus 3D beamforming is not supported. The method of embodiments of the present invention comprises: a network side determines a subframe (31) used for bearing the reference signal, determines a pilot frequency port (32) of the reference signal, and transmits in the determined subframe the reference signal configured in the pilot frequency port, where all of the pilot frequency ports comprise at least one row of horizontal-dimension pilot frequency ports and one column of vertical-dimension pilot frequency ports, the reference signal configured in the horizontal-dimension pilot frequency ports is a horizontal-dimension reference signal, and the reference signal configured on the vertical-dimension pilot frequency ports is a vertical-dimension reference signal (33). Because the embodiments of the present invention are capable of transmitting the vertical-dimension reference signal, implementation of channel estimation on the vertical-dimension pilot frequency ports is allowed, and implementation of a dynamic 3D beamforming technology is allowed.