Abstract: Objective To explore the relationship between blood glucose fluctuation and changes in electrocardiogram in elderly patients with type 2 diabetes(T2DM). Methods The clinical data of 196 elderly patients with T2DM was analyzed retrospectively. All patients were monitored by dynamic blood glucose and 24 h dynamic electrocardiogram. Blood glucose fluctuation and changes in electrocardiogram between the two groups were observed, and the correlation between blood glucose fluctuation and changes in electrocardiogram in elderly patients with T2DM was analyzed. Results Before treatment, there were 61 patients(31.12%)with hyperglycemia and 42 patients(21.43%)with hypoglycemia, and the total incidence of glucose abnormality was 52.55%. The incidence of abnormal changes in electrocardiogram of patients with abnormal blood glucose was higher than that in patients with normal blood glucose, and the difference was statistically significant(P<0.05). Logistic regression analysis results showed that abnormal blood glucose in elderly T2DM patients was influencing factor leading to abnormal changes in electrocardiogram(P<0.05). After correcting blood glucose, the incidence of abnormal changes in electrocardiogram was lower than that before treatment, and the difference was statistically significant(P<0.05). Conclusion The blood glucose fluctuation in elderly patients with T2DM is closely related to changes in electrocardiogram, and great fluctuation - in blood glucose is the influencing factor of arrhythmia and ST-T changes. The clinical monitoring of patients'blood glucose can be strengthened to reasonably control blood glucose and reduce the incidence of cardiovascular disease.