Abstract: Study the mechanism of the dead fetus that the puerperal delivered with hepatitis virus. 45 cases dead fetus were randomly selected that the puerperal delivered with hepatitis virus. The brain, thymus, heart, lungs, pancreas, liver, spleen, kidney, umbilical cord, placenta were collected and embedded with paraffin and made section. The sections were stained with HE, and observed under light microscope with the pathological methods. It was higher for the rate of the dead fetus that the puerperal delivered with IH than NIH, It was highest for the rate that fetus died in the gestational period (36-38W) of the pregnant women with hepatitis C; It was higher for the rate of the PMD?FAFAL?PO?PC?PP that the puerperal delivered with IH than NIH, The comparison results were statistically significant ( P <0 05) . The higher death rate of the fetus that the puerpecal delivered with IH than NIH was mainly due to the placenta maldevelopment which cause the amniotic fluid to be inspired into fetus lungs, further cause the fetus to have cardiopulmonary insufficiency and other dyformaties.