One of the major constraints to use of cowpea seeds is storage loss due to cowpea weevil infestation. Appropriate steaming and subsequent drying treatments have been known to alter the physicochemical characteristics of cowpea seeds, and thereby reducing losses during storage. Starch is the major component of dry seeds and its gelatinization is involved in the physicochemical changes that occur during the treatment. This research is focused on the gelatinization of starch within the cowpea seeds during steaming. Starch gelatinization is based on simultaneous heat and mass transfer reactions. A finite element model was successfully developed to describe the behavior of simultaneous heat and mass transfer. The predicted temperature and moisture profiles in the seeds agreed well with the experimental results. A kinetics of starch gelatinization was constructed and incorporated in the finite element model to investigate the mechanism of starch gelatinization during steaming. The integrated model was able to quantitatively simulate the gelatinization phenomenon.