Abstract: Because the resources in cognitive wireless networks are high dynamic, there must be a special transmission control mechanism to coordinate the transmission of each node. A novel backpressure transmission control mechanism is proposed to supply an efficient and stable end to end transmission. The novel control mechanism takes full advantage of the adjustment ability of the local nodes to solve the undesirable network conditions in a local area and make the source node making the end to end control measures softly. An extensive simulations show that the transmission control mechanism is suitable for the dynamic cognitive wireless networks, and is capable of making the end to end transmission efficient and stable.