We report group B Betacoronavirus infection in little Japanese horseshoe bats in Iwate prefecture. We then used reverse-transcription PCR to look for the coronavirus RNA-dependent RNA polymerase gene in fecal samples collected from 27 little Japanese horseshoe bats and found eight were provisionally positive. We had a success in the nucleotide sequencing of six of the eight positive samples and compared them with those of authentic coronaviruses. We found that these six samples were positive in coronavirus infection, and they belonged to the group B Betacornavirus by phylogenetic analysis. Virus isolation using the Vero cell culture was unsuccessful. Pathogenic trait of these bat coronaviruses remained unexplored.