Abstract: The variation of individual rice moisture content is significant. Grain moisture distributions were investigated during maturing, harvesting and storing by means of computer and single kernel tester. The mechanisms of moisture transferring among kernels were discussed. High temperature and high humidity climate causes high moisture content of rough rice during harvesting. Moisture distributions of rough and brown rice were compared. Moisture content of rough rice is always much higher than that of brown rice. The moisture content of hulls is the highest. Ventilation can make grain surface moisture wipe off quickly and uniformly.