Aims: Liver fibrosis and its sequel cirrhosis represent a major health care burden, and assessment of fibrosis by biopsy is gradually being replaced by noninvasive methods.In clinical practice, the determination of fibrosis stage is important, since patients with advanced fibrosis have faster progression to cirrhosis and antiviral therapy is indicated in these patients. To assess the performances of liver fibrosis during antiviral treatment by liver stiffness measurement (LSM)using Fibroscan in chronic hepatitis B (CHB) patients. Methods: We followed and evaluated treatment outcome of 56 patients with CHB, initiating their TDF regimen at Happy Veritas Clinic and Diagnostic Center. Each patient underwent transientelastography measurements, HBV quantification and serum liver marker assays before treatment with TDF, orally once daily. Results: The mean age of the patients 45±11. Before treatment LSM results indicated fibrosis stage F0 in 18(32.1%) patients, F1 in 6(10.7%), F2 in 19(33.9%), F3 in 18(16.1%), and F4 in 4(7.1%) patients. After SVR 12, SVR 24 months the mean stiffness score of F1 increased from 7.8 to 8.3kPa. F2 increased from 9.4 to 10.3 kPa, F3 decreased from 13.3 to 12.3kPa, F4 increased from 23.8 to 28.4 kPa. In table 1 shows the changes of liver stiffness by Fibroscan after treatment. There was a significant negative correlation between platelet count and liver stiffness score. Conclusions: In chronic hepatitis B patients who is receiving TDF regimen, annual LSM revealed that significant advanced fibrosis improvement slows but continues during treatment.