An outbreak of potentially lethal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or Covid-19 that appeared in last quarter 2019 leads to 574,475 death and 13,202,432 cases till 13/7/2020. Since its appearance, all scientist worldwide had hardly worked to understand the virus structure, molecular mechanism, immune response, diagnosis, and potential investigational therapeutics. Till 13 July 2020, about 41754 scientific paper and reviews according to World Health Organization were published in different subjects' area consider Covid-19. Several studies were conducted to study the relation of enviromental factor such as pollution, temperature, and humidity with the pattern of virus infection rate but there is no clear correlation between transmission pattern and enviromental factors changes. The reported viral-transmission routs are close contact and aerosol therefore the primary infection organ is lung, but the virus can infect also digestive tract, kidney, and immune cells. Several blood parameters alterations such as lymphopenia, thrombocytopenia, leukopenia with low ferritin, CD4+T and CD8+T lymphocytes and high level of C-reactive protein (CRP), lactate dehydrogenase (LDH) and creatinine kinase (CK) higher-levels of IL-6 and IL-10, and D-dimer are observed in Covid 19 patients.