Abstract: Taking into consideration that the abnormal areas aren't distributed uniformly and nodes in wireless sensor networks(WSNs) are dense and redundant,an energy-efficient deployment strategy named Nested Grid based Energy-efficient Deployment Algorithm(NGEDA) is presented for WSNs.A non-uniform deployment algorithm is designed based on physical parameter gradient distribution.The performance of NGEDA employed in environment monitoring(e.g.forest fire monitoring) is analyzed and validated by Matlab simulation.Results show that NGEDA is energy-efficient,can quickly find the abnormal area,and can describe its parameter distribution in detail.