Abstract: Appropriate storage temperature in storage room is an important condition for scientific storage and quality determination. In order to investigate the differences of internal temperatures in potatoes heaps with different weights under the same storage conditions, the semi-underground potato storage room in Inner Mongolia was taken as the experimental site, and the edible potatoes of ’Jizhang 226’ were graded according to the weights and stacked in baskets, meanwhile, the temperature data in storage process collected using sensors were analyzed and compared. Results showed that the internal temperatures of graded potatoes piles during the whole storage process presented similar change pattern, which was firstly reduced and then increased. However, the internal temperatures of graded potatoes piles with lower weights showed superior stability than that with higher weights.During the temperature decreasing stage, the internal temperatures of potatoes piles were negatively correlated with the weight of single potato, while during the temperature rising stage, the temperature rising rates in potatoes piles showed positive correlation with the single potato weight. Besides, the minimum temperatures of potatoes piles were negatively correlated with the single potato weight during the storage process, and the internal temperature stability of graded potatoes piles was better than that of the ungraded potato piles.