A method for transmitting a V2X message by means of a V2X communication device is disclosed. A V2X communication method can comprise the steps of: receiving a platooning information message from an external V2X communication device; determining, on the basis of information comprised in the platooning information message, whether or not the concatenation with a platooning group is to be formed; if it is determined that the concatenation is to be formed, transmitting a concatenation request message for requesting the concatenation to the external V2X device; receiving from the external V2X device a concatenation response message which is a response message to the concatenation request message; and forming the concatenation with the platooning group. The platooning information message can comprise information relating to a platooning group to which a vehicle having an external V2X communication device belongs.