An automatic titration system using a PC-camera with a color filter on its lens was used in the KMnO4 consumption test of tap water and distilled water in relation to blank tests. The very faint pink color of titration end point could be effectively detected by using a yellow cellophane paper as a color filter. The average hue value (Havg) of 192 pixels in the image of the sample solution being titrated was computed and followed up at regular time intervals during titration in order to detect the titration end point. The Havg decrease of 2 degrees from the average of first 10 Havgs was regarded as reaching the end point. The volume of 0.01N KMnO4 consumed by a tap water sample was 0.728±0.022ml in manual titration and 0.735±0.013ml in automatic titration (p=0.580). The volume of 0.01N KMnO4 consumed by a distilled water sample was 0.383±0.015ml in manual titration and 0.367±0.015ml in automatic titration (p=0.252). The high p-values for t-test suggested that there were good agreements between manual and automatic titration data and the automatic method proposed in this article was considered to effectively replace the manual titration.