Abstract: Based on the attenuation model of the plume,the location of plume source using maximum likelihood algorithm and the nonlinear least squares algorithm were studied.The effect of the estimation error,with different sensor number and different back ground noise,is researched by simulation.The(result) shows that better accuracy can be got by using nonlinear squares algorithm when the background noise is less.On the contrary,the maximum likelihood algorithm is robust to the much noise compared with the nonlinear squares algorithm.