Abstract:[Objective]To investigate the correlation between abnormal bone metabolism and cognitive impairment in type II diabetes mellitus(T2DM).[Materials and Methods]A total of 45 patients with T2DM who were admitted to the Second Affiliated Hospital of Shandong First Medical University from July 2020 to December 2021 were collected. The general clinical data, serum osteocalcin (OC),hemoglobin A1c(HbA1c) and the bone mineral density(BMD) were collected, evaluate the cognition of each patient. The subjects were grouped by the reference of BMD,the cognitive changes of patients between groups were compared, and the correlation between cognition and clinical related indexes, bone mineral density and osteocalcin were analyzed..[Results]The difference in MOCA scores and BMD between groups was statistically significant(P<0.05). The T2DM with osteoporosis group was lower than the other two groups,BMD and MOCA scores showed strongly positive correlation（r=0.628，P<0.001）,OC was positively correlated with BMD（r=0.733，P<0.001）, BMD alone explained 38.1% of the effect on cognition;OC alone explained 52.7% of the effect on BMD.[Conclusion]Cognitive impairment is gradually aggravated with the progression of abnormal bone metabolism in T2DM.