Purpose: The purpose of this study was to investigate about missed abortion pathophysiology, diagnosis, medical treatment and to research the trend of the study related to missed abortion. Methods: We referred a PubMed site by using search word of "missed abortion"(Limits: 3 Year, only items with abstracts, Human). Results: 37 journals with 49 papers were searched. Conclusion: 1. The study of missed abortion pathophysiology was the following. The first was that important pathologies such as molar pregnancy and placental trophoblastic disease can be diagnosed by routine histopathologic analysis of product of conception following first-trimester spontaneous miscarriages. The second was that coelomic fluid leptin concentration in missed abortion is higher than in normal. The third was that adenosine deaminae activity in serum and placenta of patients with anembryonic pregnancies and missed abortions was low. The forth was that Leptotrichia amnionii sp. nov. was the etiopathogenetic factor in missed abortion. 2. Transvaginal ultrasound assessment of irregular vaginal bleeding is effective in diagonosis of missed abortion. 3. There were medical therapy with misoprostol, mifepristone or anti progesterone for missed abortion. Misoprostol was administrated oral(sublingual) and vaginal.