We have gone through several stages of antiviral treatment for hepatitis B, from interferon for injection in the 1980s to lamivudine, the first oral nucleoside analogue marketed in China in the late 1990s, to adefovir, entecavir and telbivudine, which were subsequently marketed, oral antivirals have gone through 12 years, and after treatment, many patients with chronic hepatitis B have benefited from them, not only stopping the progression of the disease and prolonging their lives, but also However, during the long period of treatment, we found that some patients had poor response or relapse due to drug resistance. Therefore, it is expected that new and better drugs to address the hepatitis B virus will continue to be available. Tenofovir disoproxil fumarate TDF (viread) is a novel nucleotide reverse transcriptase inhibitor that was approved by the U.S. FDA in 2008 for the treatment of chronic hepatitis B in adults, and more than 30 countries and regions, including the United States, have obtained indications for TDF for the treatment of chronic hepatitis B. TDF is an ester precursor of tenofovir, which is quickly hydrolyzed orally to tenofovir and phosphorylated by cellular kinase to produce the pharmacologically active product, tenofovir diphosphate, which competes with 5′—deoxyadenosine triphosphate for entry into the viral DNA chain, and blocks DNA lengthening due to its lack of 3′-OH gene. It blocks the replication of the virus due to the lack of 3′-OH gene. It has the following characteristics: 1. Tenofovir is the nucleoside (acid) analog with the strongest anti-hepatitis B virus activity and the highest resistance barrier to date. 2. Clinical studies have shown it to have good antiviral effects in patients with HBV, HBV co-infection with HIV and in patients resistant to lamivudine. The latest research shows that tenofovir monotherapy has good efficacy and safety in the treatment of simple hepatitis B virus infection. 3. Based on the good anti-hepatitis B virus activity, safety and high genetic barrier of tenofovir, the 2009 updated AASLD guidelines recommend TDF as the first-line antiviral therapy for chronic hepatitis B. Clinical efficacy studies of tenofovir Phase III clinical trials of tenofovir in the treatment of chronic hepatitis B have shown that the resistance rate of TDF for 4 years of continuous treatment is 0, monotherapy is generally well tolerated, only 1% of treatment was discontinued due to adverse events, and no nephrotoxicity has been reported for 4 years of continuous treatment. Tenofovir in patients with ADV or poor ADV/LAM response at 24 and 48 weeks of treatment resulted in HBVDNA <69 IU/ml in 59.6% and 71.0% of patients, respectively, and HBVDNA <12 IU/ml in 44.2% and 51.6% of patients, respectively, and viral response rates were not associated with HBV genotype, baseline LAM-R and HBeAg status, but Of note was a slight decrease in virologic response rate in patients with ADV-R at baseline, but no statistical difference compared to patients without ADV-R. The overall safety profile of tenofovir in patients with decompensated cirrhosis is good and the renal safety profile is similar to that of entecavir. Tenofovir is safe for use in pregnancy, as it is a class B drug for pregnancy. Data from studies suggest that TDF is safe even in early pregnancy, but it is not known whether TDF increases the risk of miscarriage and whether breast milk administered with TDF has an effect on the growth and development of the infant. In conclusion: TDF is a nucleoside (acid) analogue with good anti-hepatitis B activity and high resistance barrier. Early clinical trials showed that TDF was better than ADV in suppressing the virus in HBeAg-positive or negative patients, and TDF alone or in combination with other nucleoside (acid) analogues was effective in those with clear LAM resistance or ADV resistance. On January 11, 2011, the State Food and Drug Administration of China approved GlaxoSmithKline's filing for clinical trials of TDF for the treatment of chronic hepatitis B. Phase III clinical trials of TDF in China have been conducted in 18 centers in China, marking a new phase of registration of TDF, a new anti-hepatitis B virus treatment, in China, which will bring new treatment options to Chinese patients with chronic hepatitis B. We look forward to more patients benefiting from this new member of the oral anti-hepatitis B virus family, tenofovir.