Abstract: Low-dose prophylactic aspirin is widely recommended for pregnant women for the prevention of preeclampsia (PE). Although the efficacy of aspirin in preventing PE has been evaluated in many studies, due to the differences in dosage, initiation time, and screening methods for the identification of women at high risk of PE and the lack of a uniform opinion on the medication regimen of aspirin, currently in China there is no consensus on the standardized treatment scheme of aspirin for the prevention of PE in clinical guidelines. Herein, we reviewed the current available evidence and the recommendations of clinical guidelines concerning the controversies about aspirin dosage as well as the timing of starting and stopping aspirin, so as to provide further guidance for clinical practice. Based on the existing research findings on and clinical practice of using aspirin for PE prevention, we suggested that PE risk screening should be conducted at 11-13⁺⁶ weeks of gestation. In addition, the recommended dose for prophylactic use of aspirin for pregnant women at high risk of PE is 150 mg/d, and the recommended minimum effective dose is 100 mg/d. Pregnant women at high risk of PE should start taking low-dose aspirin orally before 16 weeks of pregnancy. Week 36 of gestation is considered the window of opportunity for discontinuation of low-dose aspirin.