To characterize epidemiological features and estimate the economic burden of diabetes-related complications among Chinese patients with type 2 diabetes mellitus (T2DM). Patients with T2DM were extracted from the 2015 China Health Insurance Research Association Claims Database that includes 4,641,636 public basic medical insurance enrollees in 61 cities across 30 provinces. For 16 chronic complications, patients with diagnosis of a certain complication were categorized into those with the new-onset and those with the pre-existing complication. A propensity-score matching was performed to control patients’ baseline characteristics between patients with and without a certain chronic complication. The incremental medical cost and resource utilization of patients with the new-onset and pre-existing complication vs. without the complication were calculated respectively and extended to a one-year period. For 5 acute complications, the medical cost and resource utilization per event were calculated. Overall 74,507 T2DM patients with an average age of 61 years were included, among which 37,994 had ≥1 complication. The chronic complications with the top 3 highest prevalence were stroke (15.6%), diabetic peripheral neuropathy (10.9%), and angina (7.1%). Their annual medical costs were RMB 24,237; 6,937 and 30,290 for the new-onset complications, and RMB 11,588; 824 and 7,521 for the pre-existing complications, respectively. The length of days in hospital was greatest for stroke, followed by angina and diabetic peripheral neuropathy both for patients with the new-onset (20.38, 14.01 and 12.58 days, respectively) and those with pre-existing complications (7.84, 4.44 and 3.77 days, respectively). Hypoglycemia was a common acute complication, with incidences of 2.67% and 0.12% for non-severe and severe hypoglycemia, respectively. Average costs per inpatient for non-severe and severe hypoglycemia were RMB 7,272 and 11,412, respectively, with average lengths of stay of 7.55 and 9.48 days, respectively. Diabetes-related complications were associated with substantial medical costs and healthcare resource utilization in China.