Continuous queries are important in moving objects databases and spatio-temporal reasoning .The traditional synchronous updating algorithms of moving object pervasively focus on improving queries? execution efficiency, while ignore the fact that the communication cost is also the bottleneck for improving query efficiency. We propose an asynchronous updating algorithm for continuous queries of moving objects. Three types of continuous range queries are discussed in the paper. Theoretical analysis and experiment results show that our algorithm substantially outperforms the traditional synchronous updating algorithms at aspects of monitoring accuracy, communication cost and CPU load balance.