The operating characteristics of IC reactor were studied when wastewater of sweet potato starch was utilized to domesticate the granular sludge. The effect of temperature on the treatment of sweet potato starch wastewater using IC reactor was specially researched. Results showed that the COD removal rate improved gradually in the process of the granular sludge in the IC reactor was domesticated by wastewater of sweet potato starch, and the activity of granular sludge also increasingly recovered. When the domestication was finished, the volume loading rate and the COD removal rate could attain 21.9kgCOD/ (m3 •d) and 84%, respectively. When the system temperature was between 29～35°C,the COD removal rate could be above 80%. However, when the temperature decreased, the COD removal rate reduced sharply.