The present invention discloses a radio resource adaptation method between UL and DL for two-way communications between a first communication device and a second communication device, comprising steps of: receiving, by the first communication device, fed-back information in an unused part of radio resource allocated to a second communication link (UL or DL) from the second communication device to the first communication device, the fed-back information enabling utilization efficiency enhancement of radio resource allocated to a first communication link (DL or UL) from the first communication device to the second communication device; and performing, by the first communication device, resource-efficient information transmission and/or retransmission on the radio resource of the first communication link, based on the received fed-back information. The present invention further provides associated wireless communication devices.