Tenofovir can produce drug-resistant viral strains in the case of long-term use, but how long drug-resistant there is no clear data in the clinic, the general chance of drug resistance is relatively low. Tenofovir is a new nucleotide reverse transcriptase inhibitor, in the case of long-term use can produce drug-resistant viral strains, hepatitis B virus polymerase rtA194T and rtV214A variant is related to tenofovir resistance, because the current clinical cases of tenofovir resistance is too small, so there is no valid conclusion on how long tenofovir use will produce drug resistance. If a patient experiences a rebound or insignificant decrease in hepatitis B DNA while using tenofovir, the patient should be alerted to the possibility of tenofovir resistance. Missed or broken doses of tenofovir increase the likelihood of drug-resistant strains of the virus. If you need to use tenofovir, follow your doctor’s instructions and do not stop taking it without authorization.