In order to investigate the prevalence of bovine coronavirus（BCoV）in different regions and cattle population at different ages in Yunnan Province，357 fecal samples（61 diarrhea and 296 non-diarrhea samples）were collected from the cattle at different ages in 5 farms in Dali，Luliang，Shilin and Xundian from 2021 to 2022 to detect BCoV by RT-PCR，followed by analysis on the N gene sequence for BCoV positive samples. The results showed that，for the 357 samples，51 positive samples were detected，with a total detection rate of 14.29%，and they were from all the 5 farms，with a farm positive rate of 100%；the detection rates of the samples from the cattle at 1 week old，1 week to 1 month old，1 to 6 months old and over 1 year old were 10.00%，19.23%，10.81% and 17.31% respectively；those of diarrhea and non-diarrhea samples were 36.07% and 9.78%，respectively. Four complete BCoV N gene sequences were obtained by amplification，which，by analysis on homology and genetic evolution，were highly conserved，with a nucleotide homology from 99.0% to 99.8%，locating at the same sub-branch with the domestic reference strain，with close genetic relationship and the nucleotide homology from 97.7% to 99.9%；they were at the same large branch with American strain 4-17-03，7-16-23，4-17-25 and Japanese strain GF2020，with a close genetic distance；but they were at different large branch with American original strain Mebus，with a distant genetic relationship and the nucleotide homology from 98.1% to 98.2%. In conclusion，BCoV might be widely prevalent in the cattle population in Yunnan Province，especially the calves at 1 week to 1 month old，which might be caused by transportation or introduction. Therefore，it was necessary to strengthen the monitoring，control and quarantine against the virus，and speed up the development and application of corresponding vaccines.