The effective thermal conductivity of rough rice was measured at selected moisture contents, temperatures, and
bulk densities. The transient heat probe method using twin probes was used for determination of the effective thermal
conductivity. The effects of moisture content, temperature, and bulk density on the effective thermal conductivity of samples
were investigated. The observed values were compared with the values calculated from the thermal conductivity of air and
grain kernels using three kinds of structural models for thermal conductivity, i.e., series, parallel, and random heat transfer
models. A new model to predict the effective thermal conductivity of rough rice, defined by the combination of series and
parallel models, was developed, and the observed data agreed well with the values calculated from the new model.