Here, we present a systematic study of ultraconserved genomic regions in the budding yeast based on the publicly available genome sequences, in order to reveal their relationship with the adaptability or fitness advantages of the budding yeast.Results: Our results indicate that, in addition to some fundamental biological functions, the UCSs play an important role in the adaptation of S. cerevisiae to the acidic environment, which is backed up by the previous observation. Besides that, we also find the highly unchanged genes (HUGs) are enriched in some other pathways, such as the nutrient-sensitive signaling pathway. To facilitate the investigation of unique UCSs, the UCSC Genome Browser was utilized to visualize the chromosomal position and related annotations of UCSs in S. cerevisiae genome.