Post-transplantation secondary erythrocytosis (PTE) is one of the common complications of renal transplantation. Its incidence is about 10-15% and it often occurs within 2 years after transplantation. PTE is more common in male patients and in patients with well-functioning transplanted kidneys. 30% to 40% of patients with PTE resolve spontaneously. The cause of PTE is not well understood and may be related to abnormal endogenous erythropoietin metabolism, postoperative application of cyclosporine A and other immunosuppressive agents. However, a definite link between postoperative secondary erythropoiesis and preoperative application of exogenous erythropoietin (EPO) has not been found. Classical treatment goals and methods The goal is to reduce the erythrocyte pressure volume to 45% and the hemoglobin to below 165 g/L. The treatment is based on the application of angiotensin-converting enzyme inhibitors (ACEI), angiotensin receptor antagonists (ARB) and theophylline drugs. Theophylline drugs (aminophylline) are rarely used due to their high doses and the difficulty of tolerating side effects in most patients. Currently, more angiotensin-converting enzyme inhibitors are used, and the effect is obvious. Such as the choice of Lortin 10mg, once a day. The effect is usually seen after 1 week of administration. It is also supplemented with drugs such as Salvia and Chuanxiong to improve microcirculation, reduce blood viscosity, maintain stable blood pressure, and prevent cardiovascular and thrombosis complications. And avoid the application of diuretics. Patients are required to drink water every night before bedtime and must quit smoking. For those whose ACEI and ARB treatments still do not work, bloodletting therapy can be taken if necessary.