OBJECTIVE： To provide reference for rational use of estradiol （E2） preparation in clinic. METHODS： The medical records of outpatients receiving assisted reproductive technology （ART） and E2 preparation [Estradiol valerate tablets （EV）， Complex packing estradiol tablets/estradiol and dydrogesterone tablets （EP）， Estradiol gel （EG）] were collected from the reproductive medicine center of a hospital during Jan. 2016-Mar. 2017. Taking drug instruction as standard， the rationality of medical records was evaluated from aspects of indication， route of administration， contraindication， usage and dosage， treatment course， etc. At the same time， these patients were followed up by telephone or outpatient service， and their pregnancy outcomes and ADR were summarized. RESULTS： A total of 12 646 prescriptions were collected， and 7 222， 3 912， 181 and 1 331 prescriptions used EV， EP， EG and EV+EP， respectively. The types of off-label use included over-indication， over-route and over-contraindication， and the rates of off-label use rates were 100％， 11.73％ and 43.60％， respectively. A total of 5 868 ART patients were involved； 439 patients received fresh embryo transplantation， and 5 429 patients received frozen-thawed embryo transplantation， involving 720 and 11 926 prescriptions， respectively. The rates of off-label use of above E2 preparations were 100％ （except for fresh embryo transplantation patients using EG）. As of Feb. 2018， the infant-holding rates of ART patients using EV， EP， EG and EV+EP were 85.29％， 85.37％， 86.36％ and 85.45％， respectively. No relevant ADR and neonatal birth defect was found. CONCLUSIONS： The phenomenon of off-label use of E2 preparations is widespread in the reproductive medicine center of the hospital. Although there is no indication of related safety risks， evidence-based evaluation should be carried out by enlarging the sample size in clinical practice， and careful use.