Abstract:On the basis of proton balance, the end point error of strong and weak acid mixture systems and its influencing factors were discussed from data of conductivity method titration. At the same time, corresponding improvements have been made in the method of end point determination. The results show that: E _t1is greatly influenced by titrant and the concentration of strong acid; E _t2is greatly influenced by the concentration of measured object and dissociation constant of the weak acid. The method of drawing a line halftime of the process is more precise than the method of drawing a line throughout the process.