Methods for reporting a transmission mode and a UE are provided. In a novel aspect, a method for reporting a transmission mode, comprising: receiving a random access resource configuration from a base station by UE in a communication network; selecting random access resources according to a transmission mode capability of the UE, transmitting a first message by using the selected random access resources; transmitting a third message according to a random access response RAR, wherein the third message contains information of the transmission mode supported by the UE. The method for reporting the transmission and the UE provided by the invention can reduce the peak-to-average power ration of the signals transmitted by the UE or provide the higher peak rate of the uplink transmission.