The invention provides port uplink and downlink traffic array monitoring methods, devices and systems. The port uplink traffic array monitoring method comprises the following steps: core network side equipment receives a data flow sent by access network side equipment, wherein the DSCP in the data flow is used for characterizing that the bit of the service type is filled in by the access network side equipment according to the binary number corresponding to a preset service type; the bit, used for characterizing the service flow direction, in the DSCP of the data flow is filled in according to the determined flow direction of service in the data flow and the binary number corresponding to a preset service flow direction; and when a request for acquiring port uplink traffic array information is received, the filled-in DSCP in the data flow flowing through a port at the current moment is sent to network management equipment in order to enable the network management equipment to monitor the port uplink traffic array according to the filled-in DSCP. Port traffic array monitoring can be realized without additionally deploying DPI equipment.