A method of transmitting a reference signal is provided. The method is applied to a network device and includes: transmitting a first indication on a second downlink frequency domain transmission resource, wherein the first indication is used to activate a first downlink frequency domain transmission resource; transmitting a CSI-RS on the first downlink frequency domain transmission resource according to a first CSI resource configuration corresponding to the first downlink frequency domain transmission resource when it is determined that there is the first CSI resource configuration, wherein the first CSI resource configuration includes a periodicity characteristic of the CSI-RS.