A communication device for handling a transmission in an unlicensed band, comprising: a storage unit, for storing instructions; and a processing circuit, coupled to the storage unit, wherein the storage unit stores, and the processing circuit is configured to execute, the following two steps in order: performing a first channel access procedure according to a first channel access priority class for a first transmission on a channel of the unlicensed band with a network, wherein the first transmission comprises at least a sounding reference signal, SRS; wherein the first channel access priority class for the first transmission is a channel access priority class 1 defined by contention windows CW min, p and CW max, p, consecutive slot durations, m p, maximum channel occupancy time, T m cot, p, and a subset of [ CW min, p, CW max, p] of allowed sizes for the contention windows in a 3rd Generation Partnership Project, 3GPP, specification; and performing a second channel access procedure according to a second channel access priority class for a second transmission on a channel of the unlicensed band with the network, wherein the second transmission comprises a physical UL shared channel, PUSCH, transmission; wherein the second channel access priority class is defined by contention windows CW min, p and CW max, p, consecutive slot durations, m p, maximum channel occupancy time, T m cot, p, and a subset of [ CW min, p, CW max, p] of allowed sizes for the contention windows in a 3rd Generation Partnership Project, 3GPP, specification; and wherein the first channel access priority class is higher than the second channel access priority class. a storage unit, for storing instructions; and a processing circuit, coupled to the storage unit, wherein the storage unit stores, and the processing circuit is configured to execute, the following two steps in order: performing a first channel access procedure according to a first channel access priority class for a first transmission on a channel of the unlicensed band with a network, wherein the first transmission comprises at least a sounding reference signal, SRS; wherein the first channel access priority class for the first transmission is a channel access priority class 1 defined by contention windows CW min, p and CW max, p, consecutive slot durations, m p, maximum channel occupancy time, T m cot, p, and a subset of [ CW min, p, CW max, p] of allowed sizes for the contention windows in a 3rd Generation Partnership Project, 3GPP, specification; and performing a second channel access procedure according to a second channel access priority class for a second transmission on a channel of the unlicensed band with the network, wherein the second transmission comprises a physical UL shared channel, PUSCH, transmission; performing a first channel access procedure according to a first channel access priority class for a first transmission on a channel of the unlicensed band with a network, wherein the first transmission comprises at least a sounding reference signal, SRS; wherein the first channel access priority class for the first transmission is a channel access priority class 1 defined by contention windows CW min, p and CW max, p, consecutive slot durations, m p, maximum channel occupancy time, T m cot, p, and a subset of [ CW min, p, CW max, p] of allowed sizes for the contention windows in a 3rd Generation Partnership Project, 3GPP, specification; and performing a second channel access procedure according to a second channel access priority class for a second transmission on a channel of the unlicensed band with the network, wherein the second transmission comprises a physical UL shared channel, PUSCH, transmission; wherein the second channel access priority class is defined by contention windows CW min, p and CW max, p, consecutive slot durations, m p, maximum channel occupancy time, T m cot, p, and a subset of [ CW min, p, CW max, p] of allowed sizes for the contention windows in a 3rd Generation Partnership Project, 3GPP, specification; and wherein the first channel access priority class is higher than the second channel access priority class.