A communication device for handling system information, 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 instructions of: receiving a radio resource control, RRC, connection release message from a network; receiving changed system information, after receiving the RRC connection release message and before initiating a RRC connection establishment procedure, wherein the changed system information is first system information broadcasted by the network, and is different from second system information stored in the communication device; comparing a first value tag in the first system information and a second value tag in the second system information; and considering the first system information as the changed system information, if the first value tag and the second value tag are different; wherein the storage unit further stores, and the processing means is further configured to execute, the characterizing instructions of: if the RRC connection release message does not comprise the release cause, then not acquiring the received changed system information; else if the RRC connection release message comprises a release cause, and the release cause is configured with a second value different from a first value, then not acquiring the received changed system information; else if the RRC connection release message comprises a release cause, and the release cause is configured with the first value, then acquiring the received changed system information. 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 instructions of: receiving a radio resource control, RRC, connection release message from a network; receiving changed system information, after receiving the RRC connection release message and before initiating a RRC connection establishment procedure, wherein the changed system information is first system information broadcasted by the network, and is different from second system information stored in the communication device; comparing a first value tag in the first system information and a second value tag in the second system information; and considering the first system information as the changed system information, if the first value tag and the second value tag are different; wherein the storage unit further stores, and the processing means is further configured to execute, the characterizing instructions of: if the RRC connection release message does not comprise the release cause, then not acquiring the received changed system information; else if the RRC connection release message comprises a release cause, and the release cause is configured with a second value different from a first value, then not acquiring the received changed system information; else if the RRC connection release message comprises a release cause, and the release cause is configured with the first value, then acquiring the received changed system information. receiving a radio resource control, RRC, connection release message from a network; receiving changed system information, after receiving the RRC connection release message and before initiating a RRC connection establishment procedure, wherein the changed system information is first system information broadcasted by the network, and is different from second system information stored in the communication device; comparing a first value tag in the first system information and a second value tag in the second system information; and considering the first system information as the changed system information, if the first value tag and the second value tag are different; wherein the storage unit further stores, and the processing means is further configured to execute, the characterizing instructions of: if the RRC connection release message does not comprise the release cause, then not acquiring the received changed system information; else if the RRC connection release message comprises a release cause, and the release cause is configured with a second value different from a first value, then not acquiring the received changed system information; else if the RRC connection release message comprises a release cause, and the release cause is configured with the first value, then acquiring the received changed system information. if the RRC connection release message does not comprise the release cause, then not acquiring the received changed system information; else if the RRC connection release message comprises a release cause, and the release cause is configured with a second value different from a first value, then not acquiring the received changed system information; else if the RRC connection release message comprises a release cause, and the release cause is configured with the first value, then acquiring the received changed system information.