Abstract: Objective: To evaluate the accuracy of Medtrnoic-MiniMed Continuous Glucose Monitoring System （CGMS） in blood glucose measurement and it′s instructral virtue in diabtetes treatment,compared with blood glucose self-monitoring （BGSM）. Methord: Totally 46 CGMS data of 37 diabetic patients were analyisized with correlation analysis and error grid analysis to assess the correlation and coincidence between CGMS glucose values and BGSM glucose values. Results: 1.The CGMS was well toleranced in all patients. 2.The correlation and coincidence between CGMS glucose values and SGMS glucose values were favorable in all blood glucose levels. 3.Error gride analysis showed that 99.8% CGMS glucose values falled in A and B zone,and indicated that the error between CGMS glucose values and BGSM glucose values was little. 4.In some diabetic patients, optimal treatment could be done according to much more valuable information that the CGMS offered. Conclusion: In blood glucose monitoring, CGMS have some predominances, such as offering much more information about blood glucose excursion, better accuracy, and instructral virtue on diabetic treatment.