应用自动电位滴定仪的等量等当点滴定法，测定苹果、葡萄、草莓三类水果样品的可滴定酸。结果表明加标回收率为92.85%～96.65%，相对标准偏差为0.64%～1.84%，不受浸提液的颜色影响，准确度和精密度高，可以在水果品质测定中推广。

The determination of titratable acidity in apple, grape, strawberry was conducted by monotonic titration (MET) using automatic potentiometric titrator. The recovery and relative standard deviation (RSD) of the method are 92.85% to 96.65% and 0.64% to 1.84% respectively. The determination result is not affected by the color of sample, and the accuracy and precision are high. This method can be used in the determination of fruit quality.