The kidney is an important organ of the urinary system, which regulates the acid, alkaline, water and electrolyte balance of the internal environment through urination, and secretes bioactive substances such as urokinin, endothelin and erythropoietin, and participates in the metabolism of vitamin D. Its role is quite significant. Urine routine test is the most basic kidney function test. To determine the significance of renal function, a comprehensive analysis must be performed in conjunction with clinical information and other tests. 1. Patients who have been diagnosed with diabetes mellitus, hypertension, systemic lupus erythematosus and other conditions that can lead to nephropathy are easy to choose α1-MG, β2-MG, urine microalbumin and urine enzyme tests. 2. Patients who have been diagnosed with renal disease should choose functional tests for glomerulus, inlet tubule and distal tubule according to the main involvement sites: for those who mainly involve glomerulus and proximal tubule, such as glomerulonephritis and nephrotic syndrome, Ccr, Cr, BUN and α1-MG and β2-MG are optional; for those who mainly involve tubulointerstitial tubule, such as pyelonephritis, interstitial nephritis, systemic For those who mainly involve the interstitial tubular nephron, such as pyelonephritis, interstitial nephritis, systemic diseases, drug poisoning, etc., urinary enzymes, T-H protein, α1-MG, β2-MG and dilution-concentration test can be selected. 3. renal disease screening: urine routine, urine microalbumin, urine β2-MG, blood β2-MG, blood BUN, Cr , UA. Renal function items: 1. urea nitrogen (BUN) 2. creatinine (Cr) 3. carbon dioxide (CO2) 4. uric acid (UA) 5. endogenous creatinine clearance (Ccr) 6. serum, urine β2 microglobulin (β2-MG) 7. urine, serum α1- MG 8. urinary microalbumin 9. urinary transferrin 10. urinary immunoglobulin 11. urinary total protein