A communication device for handling measurement gaps, comprising: a storage device; and a processing circuit, coupled to the storage device, wherein the storage device stores, and the processing circuit is configured to execute, instructions of: receiving a first measurement gap configuration from a base station, BS, on a first carrier, wherein the first measurement gap configuration configures a first plurality of measurement gaps for the communication device, wherein the first measurement gap configuration is associated to a first serving cell; determining a first plurality of gap locations of the first plurality of measurement gaps in a timeline according to system time acquired from the BS and the first measurement gap configuration; performing at least one first measurement on a second carrier in at least one of the first plurality of measurement gaps according to the first plurality of gap locations; detecting a failure; releasing the first measurement gap configuration in response to the failure; receiving a second measurement gap configuration from the BS after performing radio resource control, RRC, connection reestablishment; and performing measurement according to the second measurement gap configuration after recovering from the failure or performing the RRC connection reestablishment procedure successfully, wherein the first measurement gap configuration is a carrier-specific measurement gap configuration, and characterised in that, the second measurement gap configuration is a user equipment, UE,-specific measurement gap configuration which is applied to all carriers on which the UE is performing receptions. a storage device; and a processing circuit, coupled to the storage device, wherein the storage device stores, and the processing circuit is configured to execute, instructions of: receiving a first measurement gap configuration from a base station, BS, on a first carrier, wherein the first measurement gap configuration configures a first plurality of measurement gaps for the communication device, wherein the first measurement gap configuration is associated to a first serving cell; determining a first plurality of gap locations of the first plurality of measurement gaps in a timeline according to system time acquired from the BS and the first measurement gap configuration; performing at least one first measurement on a second carrier in at least one of the first plurality of measurement gaps according to the first plurality of gap locations; detecting a failure; releasing the first measurement gap configuration in response to the failure; receiving a second measurement gap configuration from the BS after performing radio resource control, RRC, connection reestablishment; and performing measurement according to the second measurement gap configuration after recovering from the failure or performing the RRC connection reestablishment procedure successfully, wherein the first measurement gap configuration is a carrier-specific measurement gap configuration, and characterised in that, the second measurement gap configuration is a user equipment, UE,-specific measurement gap configuration which is applied to all carriers on which the UE is performing receptions. receiving a first measurement gap configuration from a base station, BS, on a first carrier, wherein the first measurement gap configuration configures a first plurality of measurement gaps for the communication device, wherein the first measurement gap configuration is associated to a first serving cell; determining a first plurality of gap locations of the first plurality of measurement gaps in a timeline according to system time acquired from the BS and the first measurement gap configuration; performing at least one first measurement on a second carrier in at least one of the first plurality of measurement gaps according to the first plurality of gap locations; detecting a failure; releasing the first measurement gap configuration in response to the failure; receiving a second measurement gap configuration from the BS after performing radio resource control, RRC, connection reestablishment; and performing measurement according to the second measurement gap configuration after recovering from the failure or performing the RRC connection reestablishment procedure successfully, wherein the first measurement gap configuration is a carrier-specific measurement gap configuration, and characterised in that, the second measurement gap configuration is a user equipment, UE,-specific measurement gap configuration which is applied to all carriers on which the UE is performing receptions.