An apparatus for Device-to-Device, D2D, communication, the apparatus located in a first user equipment, comprising: a first receiving module, configured to receive configuration message(s) from a network, wherein configuration information about D2D discovery signal(s) is carried in the configuration message(s); a detection module, configured to detect D2D discovery signal(s) from a second user equipment according to the configuration information carried in the configuration message(s); a transmitting module, configured to transmit a request message to the network according to the detection of a D2D discovery signal detected by the detection module, wherein the request message is used to acquire the identity of the second user equipment transmitting the detected D2D discovery signal(s); and a second receiving module, configured to receive a response message sent from the network, wherein the identity of the second user equipment or rejection information indicating the rejection to the discovery of the second user equipment by the first user equipment is carried in the response message; characterized in that configuration information about D2D discovery triggering signal(s) is also carried in the configuration message(s); and the transmitting module is also configured to transmit the D2D discovery triggering signal(s) after the first receiving module receives the configuration message(s) and before the detection module detects the discovery signal, wherein the D2D discovery triggering signal(s) is used to trigger the second user equipment which receives the D2D discovery triggering signal(s) and has a peer discovery requirement to transmit the D2D discovery signal(s). a first receiving module, configured to receive configuration message(s) from a network, wherein configuration information about D2D discovery signal(s) is carried in the configuration message(s); a detection module, configured to detect D2D discovery signal(s) from a second user equipment according to the configuration information carried in the configuration message(s); a transmitting module, configured to transmit a request message to the network according to the detection of a D2D discovery signal detected by the detection module, wherein the request message is used to acquire the identity of the second user equipment transmitting the detected D2D discovery signal(s); and a second receiving module, configured to receive a response message sent from the network, wherein the identity of the second user equipment or rejection information indicating the rejection to the discovery of the second user equipment by the first user equipment is carried in the response message; characterized in that configuration information about D2D discovery triggering signal(s) is also carried in the configuration message(s); and the transmitting module is also configured to transmit the D2D discovery triggering signal(s) after the first receiving module receives the configuration message(s) and before the detection module detects the discovery signal, wherein the D2D discovery triggering signal(s) is used to trigger the second user equipment which receives the D2D discovery triggering signal(s) and has a peer discovery requirement to transmit the D2D discovery signal(s).