In order to obtain a simple and reliable method for volatile fatty acid concentration and bicarbonate alkalinity, Nordmann titration method and instrument method were chosen in lab-scale CSTRs for chicken manure. The accuracy was compared and correction of titration method was made. The result showed that the Nordmann titration method and instrument method for VFA and TIC concentration determination were significant difference, and the mean relative error was more than 50%. After correction, the mean relative error was significantly reduced and lower than 10% when the organic load was higher than 4.0g/(L·d). It means that the modified titration method could achieve more simple and accurate determination of VFA and TIC concentration. Also, as the total VFA concentration measured by the modified titration method had a good correlation with the acetic acid concentration measured by gas chromatography, the modified titration method could estimate the acetic acid concentration. Compared to pH value, VFA/TIC ratio measured by modified titration method could realize early warning of acidification.