Diabetes mellitus urine protein 3+ should go to endocrinology or nephrology. Diabetic patients with urinary protein 3+ is partly due to diabetic nephropathy, partly due to nephrotic syndrome, glomerulonephritis, urinary tract infections and so on. Diabetic patients with a long course of disease and poor long-term glycemic control are likely to have proteinuria due to diabetic nephropathy and should consult an endocrinologist. Urine protein 3 +, 24-hour urine protein quantitative greater than 3.5 grams, combined with hypoproteinemia, may be nephrotic syndrome. Proteinuria 3+ combined with hematuria and hypertension may be glomerulonephritis. Proteinuria 3+ with urine leukocytosis, increased urinary bacteria and symptoms of urinary frequency, urgency and pain may be urinary tract infection. These conditions should be seen in nephrology. Diabetes mellitus urine protein 3 + should be further checked 24-hour urine protein quantification, renal function, etc., to understand the quantification of urine protein and the stage of kidney disease. If necessary, complete renal puncture biopsy to understand the cause of urinary protein. Diabetic urine protein 3 + should be timely to the hospital endocrine and nephrology department, under the guidance of the doctor’s treatment.