In the present study we used Reverse transcription polymer chain reaction (RT-PCR) assay for detecting of bovine corona virus, We evaluated presence of bovine corona virus (BCoV) in diarrheic fecal samples in age (1–30) day.(152) faecal samples from diarrheic calves were collected from four Iraqi governorates (Al-Qadisyia, Babylon, Wassit and Najaf). 10 (6.57%) out of 152 were positive to bovine corona virus. This study is the first detection of bovine corona antigen in Iraq. The results suggest that RT-PCR is more sensitive than other method to detect BCoV, especially in subclinical cases and Because these animals shed a low amount of virus in faeces and more animal show clinically normal we need to apply sensitive techniques, such as RT-PCR.