For establishing a simple and accurate method for testing the moisture retention ability of tobacco, the effects of testing method, humidity controlling measures, specimen size and cut tobacco structure on the accuracy of test results were examined. It showed that the testing results would be more accurate by taking specimen size as big as possible and of even structure, equilibrating the tobacco sample in a sulfuric acid desiccator, and placing the desiccator in a climate chamber of the same humidity. The variation of moisture content in cut tobacco in the course of equilibration was determined by gravimetric method.