Estimating placental function is highly desirable, as impaired placental function is associated with FGR and poor neonatal outcome. This study evaluated variations of T2* after oxygen inhalation of 8 pregnant women in the second and third trimesters using quantitative mDixon-Quant imaging. The hyperoxic T2* after oxygen inhalation was significantly higher than baseline T2* which defined as before oxygen inhalation. The change of baseline T2* and hyperoxic T2* was significantly negative correlated with gestational age. The result showed that |△T2*| was correlated with placental function. We speculate T2* based mDixon-Quant imaging is useful in noninvasive assessment of placental function.