Abstract: Decision fusion rules for multihop wireless sensor networks in fading channel are investigated.Optimal likelihood ratio rule has been presented under the assumption of Rayleigh channel model.However,acquiring real-time channel information may be too costly for resource constrained sensor networks.Suboptimal likelihood ratio fusion rule is proposed which requires only the statistical knowledge of channel.In addition,when the channel signal-to-noise ratio(SNR) is high and low,the reduced forms are also derived respectively.Theoretical analysis and simulations show that suboptimal fusion rule needs much less computation and information,yet exhibits only slight performance degradation.Suboptimal fusion rule is practicable for decision fusion system in resource constrained multihop wireless sensor networks.