In this paper, the notion of ''regularity'' is introduced to describe the structural features of DNA sequences. This notion expands the ''latent periodicity'' term. The novel method for revealing regularity based on the runs test is described. The search of regular sequences in eukaryotic promoters has shown that more than 60% of them possess a regularity property on statistically significant level. Possible biological functions of regularity are discussed together with the possibility of using this characteristic for performing promoter annotation.
