High urinary amylase and normal blood amylase are often seen in the recovery period of acute pancreatitis. When acute pancreatitis occurs, blood amylase usually becomes elevated 2-12 h after the onset of the disease and lasts for 3-5 days. For urinary amylase, it will be elevated only 12-24h after the onset of the disease, and its elevation is later than the elevation of blood amylase, and the duration of urinary amylase is 3-10 days. If in the recovery period of acute pancreatitis, that is, in the late stage, the blood amylase has dropped to normal, but the urinary amylase still continues to rise, the situation of high urinary amylase and normal blood amylase will occur. Both blood amylase and urinary amylase are indicators of acute pancreatitis, and for urinary amylase, the most important significance applies to patients who present late to the clinic because urinary amylase elevation lasts for a longer period of time.