|Background: Previous studies have reported that enhanced continuity of care prevented a sudden worsening in progress among chronic disease patients, and as a result was favorable for efficient spending of health care funds. This study aims to estimate the continuity of care of Korean with diabetes and to identify factors affecting the continuity of care. Methods: This study used the Korean National Health Insurance Claims Database which includes E11 (ICD-10) as a primary or secondary disease as of 2006. Study population is 1,160,725 type 2 diabetics (20-84 years). Continuity of Care Index (COC), Modified, Modified Continuity Index (MMCI), and Most Frequent Provider Continuity (MFPC) were used as indexes of continuity of care. Results: The continuity of care in the study population was 0.94±0.10 as calculated by MMCI, 0.91±0.16 as calculated by MFPC and 0.86±0.23 as calculated by COC. The lower continuity of care was shown in the patients who were female, 65 and over years old, Medical Aid recipients, 13 times or more visitors, hospital users as main attending medical institution, patients experienced hospitalizations or comorbidities. Conclusion: The continuity of care for adult patients with type 2 diabetes was high in Korea, and showed variation according to patients` characteristics. This result provides empirical evidence for policymakers to develop or strengthen programs for managing patients showing low continuity of care.