The invention is applicable to the field of data communication and provides a method and a system for network congestion management. The network comprises a core network entity with a congestion detection function and an upstream network entity capable of responding to congestion notification information. The invention is characterized in that the method comprises the following steps: the core network entity sends the congestion notification information to the upstream network entity when detecting the congestion situation; the upstream network entity reduces the data transmission rate by a certain step value according to the received congestion message information and resets a timer or a counter for counting the number of data packets; and the timer or the counter triggers the upstream network entity to enter a rate recovery stage when overflows. When the timer or the counter overflows, the upstream network entity increases the data transmission rate and reduces the waste of the network bandwidth.