Abstract： Objective To compare the clinical benefit between continuous subcutaneous insulin infu-sion(CSⅡ) and continuous intravenous insulin infusion (CVⅡ) in treatment of elderly patients with diabetic ketoaciduria. Methods 120 elderly patients with diabetic ketoaciduria were randomized into two groups, one was CSⅡ group by a portable insulin pump(60 cases), the other was CVⅡ group (60 cases), and compare two grouds on the clinical therapeutic benefit and cost benefit. Results The glucose level, therapeutic time [(6.28±1.6) dvs (9.68±1.8) d]; the time to normal ketonuria [(17.0±3.8) hvs (31.3±6.4)]; insulin dosage [(43.8±7.8) u/d vs (54.9±6.8) u/d], the rate of hypoglycemia [(1.62±0.54)vs(0.56±0.34)] were better than CVⅡ, and expense (RMB Yuan) [(446.8±37.8)]vs [(245.9±6.8)], mean cost (RMB Yuan) [(446.8±37.8))] vs [(245.9±6.8)]) were greater than CVⅡ, while the total cost (RMB Yuan) [(3567.50±73.82)]vs[(4131.53±86.42)] was less than CVⅡ,The insulin dosage and HbA1>c of CSⅡ group were significantly lower CSⅡ group after 3 months. Conclusion This study shows that CSⅡ is the refera-ble one for the elderly patients with diabetic ketoaciduria, and the efficacy last longer to medium-or long-term.