Abstract: In cloud computing environment,an effective live migration algorithm of virtual machine can greatly reduce energy consumption and the violation rate of SLA.This work proposes an improved virtual machine live migration algorithm,which adopts the double thresholds strategy,the virtual machine selection strategy based on the minimum cost of migration,and the probabilistic selection strategy of the target physical nodes.The simulation experiments show that the proposed algorithm can reduce the system energy consumption and the SLA violation rate in the virtual machine live migration.