Bay aspirin, or aspirin enteric-coated tablets, is the drug of choice for the prevention and treatment of coronary heart disease. Bay aspirin is an enteric preparation and is recommended to be taken in the morning on an empty stomach. 1. The high incidence of cardiovascular events is often between 6:00 am and 12:00 noon. In order to reduce the stimulation of aspirin on the gastrointestinal tract, the aspirin commonly used in clinical practice is enteric-soluble, and it takes 3-4 hours to reach the peak of blood dose after taking the drug. If the drug is taken at 8 or 9 o’clock in the morning, the peak effect of the drug is after noon, which does not provide the best protection for the high incidence of cardiovascular events. In addition, people sleep at night, blood flow is slow, no water at night, blood viscosity is also high, and the night is the time when the most new platelets, easy to form blood clots, so it is better to take it in the morning or in the evening. Considering the convenience of taking time and avoiding missed doses, it is recommended to take it in the morning. 2. Enteric aspirin is taken on an empty stomach, which is more conducive to the absorption of the drug and improves the utilization of the drug; in addition, because aspirin damages the stomach, the time it stays in the stomach should be minimized to reduce the damage. Enteric-type aspirin is not easily absorbed in the acidic environment of the stomach and is more easily absorbed in the alkaline environment of the intestine, so it is more effective when taken on an empty stomach. If a high-quality, precisely enteric aspirin is chosen, then taking it in the morning on an empty stomach should be the best choice. Therefore, it is recommended to choose the right dose based on adherence to the medication to achieve better clinical results and to prevent GI damage at the same time.