A communication device for handling a Hybrid Automatic Repeat Request, HARQ, timing, comprising: a storage device, storing instructions of: receiving a first downlink, DL, control information, DCI, with a first cyclic redundancy check, CRC, scrambled with a Cell Radio Network Temporary Identifier, C-RNTI, from the network; communicating (302, 402) with a network according to a first HARQ minimum timing and the first DCI; transmitting a first message comprising an indication of support of a second HARQ minimum timing to the network according to the first HARQ minimum timing, wherein the first HARQ minimum timing is greater than the second HARQ minimum timing; receiving a second message configuring the second HARQ minimum timing from the network according to the first HARQ minimum timing; receiving a second DCI with a second CRC scrambled with the C-RNTI from the network, wherein the first DCI and the second DCI have the same DCI format; and communicating (308, 404) with the network according to the second HARQ minimum timing and the second DCI in response to the second message; and a processing circuit, coupled to the storage device, configured to execute the instructions stored in the storage device. a storage device, storing instructions of: receiving a first downlink, DL, control information, DCI, with a first cyclic redundancy check, CRC, scrambled with a Cell Radio Network Temporary Identifier, C-RNTI, from the network; communicating (302, 402) with a network according to a first HARQ minimum timing and the first DCI; transmitting a first message comprising an indication of support of a second HARQ minimum timing to the network according to the first HARQ minimum timing, wherein the first HARQ minimum timing is greater than the second HARQ minimum timing; receiving a second message configuring the second HARQ minimum timing from the network according to the first HARQ minimum timing; receiving a second DCI with a second CRC scrambled with the C-RNTI from the network, wherein the first DCI and the second DCI have the same DCI format; and communicating (308, 404) with the network according to the second HARQ minimum timing and the second DCI in response to the second message; and receiving a first downlink, DL, control information, DCI, with a first cyclic redundancy check, CRC, scrambled with a Cell Radio Network Temporary Identifier, C-RNTI, from the network; communicating (302, 402) with a network according to a first HARQ minimum timing and the first DCI; transmitting a first message comprising an indication of support of a second HARQ minimum timing to the network according to the first HARQ minimum timing, wherein the first HARQ minimum timing is greater than the second HARQ minimum timing; receiving a second message configuring the second HARQ minimum timing from the network according to the first HARQ minimum timing; receiving a second DCI with a second CRC scrambled with the C-RNTI from the network, wherein the first DCI and the second DCI have the same DCI format; and communicating (308, 404) with the network according to the second HARQ minimum timing and the second DCI in response to the second message; and a processing circuit, coupled to the storage device, configured to execute the instructions stored in the storage device.