Abstract： Objective To study the relationship among hydrops fetalis(over 28 gestational weeks),Mirror syndrome and preeclampsia(PE). Methods Clinical data of 13 cases of hydrops fetalis were analyzed and relative publications were reviewed. Results Eight out of the 13 cases were diagnosed as PE,and 5 were Mirror syndrome.Serious maternal complications occurred in all cases with either Mirror syndrome or PE. Conclusions Fetaland placental hydrops was closely related with maternal symptoms.Clinicians should be aware of this condition and detect Mirror syndrome in time so as to prevent its progress to PE.However,the pathogenic mechanism remains to be fully elucidated.More attention should be paid to both mothers and the hydrops fetalis.