Due to the endocrine changes and the increased burden on the liver during pregnancy, even pregnant women who do not carry hepatitis B surface antigen may have abnormal liver function. There are many reasons for liver function abnormalities during pregnancy, but a slight increase (within one times of the normal range) is not necessary for medication, and attention to rest and nutrition is sufficient. For hepatitis B surface antigen carriers, if liver function abnormalities occur during pregnancy, the first thing to do is to find out the cause, if there is any other liver disease other than hepatitis B, you should actively treat and eliminate the cause. If there is no other cause, different treatment can be done according to the level of transaminases. 1. If ALT is less than 80U/L and there is no symptom, we can suspend the treatment and continue to observe. Oral hepatoprotective drugs, such as S–adenosylmethionine and reduced glutathione, which have less effect on the fetus, can also be given. 2, ALT ≥ 80U / L, should start antiviral treatment with drugs safer for fetal development, priority recommended tilofovir, can also use tebivudine, lamivudine. The latter two have a higher risk of drug-resistant mutations and should be replaced with entecavir after the birth of the child. 3. If jaundice has appeared and is on the rise, one should be alert to the occurrence of severe hepatitis and early use of antiviral therapy is recommended. For pregnant women who have been diagnosed with severe hepatitis should terminate the pregnancy early and treat it actively. 4. Remember to vaccinate the child against hepatitis B within 24h after birth and inject hepatitis B immunoglobulin within 12h after birth under doctor’s instruction.