Disclosed are a method and device for transmitting control information, to provide a control information sending manner based on a diversity transmission mode. The method for transmitting control information includes: determining the transmission of a plurality of enhanced control channel units (E-CCE) of an enhanced physical downlink control channel (E-PDCCH), each E-CCE containing the same number of enhanced resource unit groups (E-REGs), and a plurality of E-REGs contained in each E-CCE respectively belonging to a different frequency resource block (RB); and bearing each piece of downlink control information (DCI) to be transmitted over the E-PDCCH into at least one E-CCE for transmission. It is realized that each portion of one piece of DCI is respectively borne onto a plurality of frequency bands corresponding to the E-PDCCH for transmission, improving the stability and reliability of DCI transmission.