The Covid-19 pandemic created by the 2019 Coronavirus-nCov has become one of the biggest health problems of the current century. Because this disease is new in human society and has no previous history, so our information about it is incomplete, and researchers are trying to study with extensive clinical studies and changes in the human body caused by the function of this virus. It is clear that the purpose of these studies is to find ways to prevent and treat the disease and ultimately fight the virus. D-Dimer is one of the products of fibrin degradation in the body that can be measured in the blood. As the fibrin lysis process increases in coagulation disorders, the amount of this product in the blood will also increase and indicate the severity of the disease. In Covid-19 disease, the activity of coagulation cascade is increased by several mechanisms that are still under investigation, and this leads to an increase in the amount of D-Dimer in the blood of patients. According to studies, the higher the amount of D-Dimer in patientschr('39') blood, the worse the patientchr('39')s condition and the more medical care he will needs. In this review study, different approaches to D-Dimer in Covid-19 disease and related therapies have been investigated.