Objective:To study the relationships between the resting heart rate(RHR) and the cognitive function of patients with type 2 diabetes mellitus (T2DM). Methods:Cognition was evaluated with questionnaires in 140 T2DM patients. The RHR was divided into three groups: <75 beats/min(bpm) group(65 cases),≥75 bpm and <85 bpm group(44 cases) and ≥85 bpm group(31 cases). The cognitive levels were compared among the three different RHR groups. Results:① There were significantly differences on the immediate memory of mini-mental state examination(MMSE) and naming picture,and the executive function and the linguistic capacity among the three groups(P < 0.05). ②It has no difference among the three groups in sex,age,the educational level,the duration of diabetes,combined hypertension or not,systolic blood pressure(SBP),hemoglobin A1c(HbA1c),cholesterol(TC),triglyeride(TG),high density lipoprotein(HDL-C),low density lipoprotein(LDL-C),lipoprotein(a) [LP(a)] and thyrotropic stimulating hormone(TSH) except diastolic blood pressure (DBP),the albumin/creatinine ratio in urine (UAIB/Cr) and the high sensitivity C-reactive protein (HsCRP). ③The RHR has negative corrections with the total score,orientation and linguistic capacity of MMSE,and naming picture,filling the lack of picture among the three groups (P < 0.05),and the executive function,composition of a picture and memory of MMSE(P < 0.01). ④There was a significant difference on RHR between UAIB/Cr <30 mg/g group and ≥30 mg/g,<300 mg/g group. And the RHR has prominent different between HsCRP ≥5 mg/L group and <5 mg/L group. Conclusion:The RHR has obvious correlation with cognitive function of patients with T2DM. RHR higher,damaged domains of cognition more.