Abstract: In order to obtain water affected to the mechanics features and acoustic- electricity features of the coal sample, a tensile experiment was conducted on t he dry coal sample and saturated coal sample. The variation differences between the stress strain and acoustic- electric signal of the dry and saturated coal samples du ring the tensile process were compared and analyzed. The study showed that during the tensile process, the coal sample had experienced a stress liner increasing, pla stic increasing and tensile fracturing stages and the electromagnetic radiation and acoustic emission signal were basic synchronous correspondence to the deformation fracturing of the coal sample .At the initial loading period, the acoustic and electric signal was low and when a plastic deformation or a fracturing deformation occurred, t he acoustic- eclectic signal was rapidly increased to the peak. Water could make the tensile strength of the coal sample reduced by 31 .5% and could make the tensile s tress increased by 101. 1%. Water could reduce the strength and increase the plasticity of coal sample to make the acoustic- electric signal attenuation. The monitorin g, measurement and analysis on acoustic- electric signal variation amplitude of the coal sample could evaluate the influence degree of mechanical property and acousti C- electricity characteristics of water to coal sample.