Arthrospira platensis was collected from Lake Bayannur and adjacent alkaline lakes located in the Mo Us Sandy Land in the Erdos Plateau in China. After subjecting the samples to temperatures of 5ºC, 0ºC, and -5ºC for 5 days, algal morphology and ultrastructure were observed. There were minimal differences in the morphological and anatomical structures of A. platensis incubated at 5ºC and 0ºC; at -5ºC, however, significant variations were seen, including a significant decrease in the number of intact trichomes due to breakage, thinner cell walls, disappearance of phycobilisomes, reduced clarity of thykaloid membranes, an increase in carboxysome volume, a reduction in lipid body size, and an increase in the number of polyglucan granules. Additionally, longitudinal cell walls became wave-shaped while cross walls became arc-shaped. Erdos Plateau A. platensis appears to be a typical low-temperature Arthrospira strain because of its similar response at 5ºC and 0ºC but divergent response at - 5 ºC. These results could offer valuable insights into the management of criticality at low temperatures in industrial cultivation of the Erdos lakes’ strain of A. platensis.