A new model for the temperature rise of an infinite medium with a heat source of a cylindrical copper block of known specific heat in a vacuum adiabatic cup of daily use is developed for simultaneous determination of three basic thermal properties of the cereal grain powders. After the cup was filed with the powder and the heater was switched on, the transient temperature of the block and the powder at 5mm from the block surface was measured, and the thermal properties were determined by fitting theoretically calculated curves with assumed parameters to the measured curve. Thermal properties of three kinds of wheat flour(soft, midle and hard) , rye flour, rice flour, soyameal flour and corn starch at 13% w.b. were, respectively, 1.894×10^<-4>, 1.785×10^<-4>, 1.895×10^<-4>, 2.187×10^<-4>, 2.269×10^<-4>, 2.244×10^<-4>, 2.192×10^<-4>(m^2·h^<-1>)on thermal diffusivity, 0.0409, 0.0461, 0.0383, 0.0450, 0.0539, 0.0408, 0.0348(W· m^<-1>·K^<-1>)on thermal conductivity, and 1.497, 1.524, 1.237, 1.484, 1.433, 1.180, 1.096(kJ·kg^<-1>·K^<-1>)on specific heat. The specific heat of α-Alumina powder were measured also to assure the accuracy of the method, and the value was agreed well with the standard value of the specific heat for DSC measurement.