In the past, we advocate children to start brushing their teeth at the age of 3. But nowadays, it seems that many children’s teeth are decayed before they are 3 years old. For example, bottle caries can occur within one year of age. Therefore, we now advocate that children should have their first teeth cleaned. The parents should use a finger toothbrush or a clean gauze dipped in water or light tea to clean. When the child is able to master the toothbrush, the parents should teach the child the correct way to brush the teeth, or they can go to the dental hospital and ask the preventive care doctor to teach the brushing method. However, children are young and have poor self-awareness, so mothers and fathers must supervise them to make them develop the good habit of brushing their teeth in the morning and evening.