Abstract: The surface tension of distilled water, tap water, and supplied water in reservoir were measured by pull-off method and laser diffraction method. The Raman spectra at room temperature of these specimens were tested by Laser Raman spectrometer. The test results indicates that the surface tension of water decreases with temperature increasing and rises with the increasing of the soluble impurities' concentration. The surface tension of three water specimens ranks in descending order: source water, tap water, and distilled water. We analyzed the Raman spectra of these water samples and concluded that with the increasing of impurity ions' concentration, the relative intensity of Raman peaks decreases, and the peaks broaden with asymmetric shape. The research results f show that surface tension can be used as an important parameter to test the quality of water.