In the process of t reat ing indust rial circulating water, the concent rat ion of organic and inorg anic compoundsare get ting hig her g radually.The majority of organisms in the indust rial ci rculating water sy stem, w hichare the nut rit ive sources of the microorg anism, are biodegradable.Suitable circumstances and suf ficient nutrimentsmake i t possible for the microorganism to reproduce heavily and form biolog ical sludge.The biologicalsludge can bring lots of obst ructions in the operatio n of the w hole system.Bactericide tradit ionally takes effectthroug h destroying the living process of the microorganism directly, as w ell as the uncleus, so as to control thereproduction.While the bactericide is dest roying the bacteria, it is harmful to our human bodies and causes environmentalpollutio n.But Tallofin finishes bacteria control by physical methods, and is harmless to human bodiesand the environment.Therefore, an experiment at the Thi rd Ci rculating Water Unit has been made to evaluatei ts efficiency and determine the optimum adding methods by t racking analy sis of water quality.