Abstract: The existing methods and techniques of rice viscosity measurement were analyzed and the mechanism in measuring rice viscosity based on material characteristics was investigated in this paper. Then, an automatic system for measuring viscosity of cooked rice was developed and quantitative characteristics used to express rice viscosity by the average slope of unloading distortion curve were established. Results showed that the system could distinguish the viscosity difference between rice varieties and detect the change of rice viscosity with cooking time for the same variety. Therefore, this system can meet the requirements in assessing and evaluating rice viscosity, which is an important factor for cooked rice quality, and provide a convenient and accurate way for rice quality measurement.