The fetal structures including fat change vigorously during the development progress. In this study, by using 2-point Dixon method, we demonstrated that the fetal fat development followed a predictable chronological sequence in terms of both location and composition. The fat at face appears the earliest at 22-23 weeks, followed by subcutaneous fat of other body part in the order of buttock, thigh, posterior neck, upper arm and lower back. Most subcutaneous fat could be well visualized at 27-28 weeks. The fat at deep part appeared later. The fat fraction in all body part gradually increased as the development progress.