Objective. A novel parameter acquired from conventional B-mode sonographic videos was introduced in this study, and its diagnostic accuracy for evaluation of hepatic fibrosis was investigated. Methods. Twenty-eight patients with chronic hepatitis B and 8 patients with hepatic cysts in the right lobe (controls) were enrolled. B-mode sonographic videos of hepatic motion under the ensisternum in the sagittal plane were captured during peaceful breathing. Maximal accumulative respiration strain (MARS) values of hepatic tissue were obtained after image analysis. METAVIR scoring after liver biopsy was considered the standard. First, the relationship between MARS and the fibrotic stage was studied; and second, receiver operating characteristic (ROC) curves were used to assess the accuracy of MARS for evaluation of the fibrotic stage. Results. When the transducer was placed in the sagittal imaging plane under the ensisternum during the whole respiratory period, the hepatic tissue motion was almost in the same plane. The MARS values (mean +/- SD) were 29.44% +/- 10.44% in the FO group (no fibrosis; n = 8), 19.30% 9.10% in the F1 group (portal fibrosis without septa; n = 8), 18.09% +/- 7.36% in the F2-F3 group (portal fibrosis with few septa or numerous septa without cirrhosis; n = 12), and 14.16% +/- 4.18% in the F4 group (cirrhosis; n = 8). The Spearman correlation coefficient between MARS and the fibrotic stage was 0.516 (P = .001). The diagnostic accuracy rates, expressed as areas under the ROC curves, were 0.87 for mild fibrosis (F >= 1), 0.72 for substantial fibrosis (F >= 2), and 0.75 for cirrhosis (F = 4). Conclusions. Maximal accumulative respiration strain attained from B-mode sonographic videos of hepatic tissue is a new, convenient, economical, and promising noninvasive parameter for assessment of hepatic fibrosis in patients with chronic hepatitis B.