Fetal growth restriction（FGR）means that the fetus does not reach its biological growth potential due to impaired placental function caused by a variety of factors.FGR is one of important causes of perinatal death and other adverse outcomes.Ultrasound evaluation of fetal growth and development is crucial for clinical diagnosis of FGR.Once FGR is diagnosed during the pregnancy，the classification should be performed based on the time of onset and the potential etiology（especially structural abnormalities）since they are closely associated with the prognosis.This helps to provide better clinical treatment and management and to reduce the risk of adverse maternal and fetal outcomes.