The temperature and humidity in our dispensary and that in the cartridge of a fully-automatic tablet packaging machine were analyzed based on the simple assumption that the humidity in the dispensary and the cartridge are about the same every morning and that the water content of the cartridge stays constant over the whole day.From the results of the analysis,an equation for predicting the temperature and the humidity in the cartridge was derived.It enables the temperature and humidity in the cartridge of the fully-automatic tablet packaging machine to be simply predicted solely on the basis of the temperature and humidity in the dispensary.Good agreement between the predicted temperature and humidity in the cartridge and actual measurements confirmed the applicablilty of the equation to this situation and we conclude that it is a useful means of predicting the temperature and humidity in the cartridge.