A transmission apparatus and method of status indication and a communication system. The transmission method of status indication includes: determining whether an RLC layer has successfully received all RLC PDUs of uplink data when a base station receives the uplink data transmitted by a UE; and transmitting PDCCH information to the UE, in a case where the RLC layer has successfully received all the RLC PDUs of the uplink data; the PDCCH information is used to indicate that the uplink data have been successfully received and/or the UE is permitted to enter into a DRX status. Hence, not only transmission of RLC status report may be reduced and transmission efficiency of the whole system may be improved, but also the UE may be made to enter into the DRX status as fast as possible and power consumption of the UE may be lowered.