Abstract: In the DS-TE networks the preemption provides the high priority business with reliable service quality, and it will be more effective especially when a network overload or node and link failure occurs. An adaptive preemption algorithm is therefore proposed to adapt to the bandwidth demand for new LSP by strengthening the control of the LSR over LSP resources. To avoid the setting of parameters, the adaptive preemption algorithm is divided into A-minconn and A-minpri. Simulation results showed that the adaptive preemption algorithm is obviously superior to the conventional algorithm in the preemption performance including bandwidth, priority and the numbers required.