The nucleotide sequences of three independent fragments (designated no. 3, 4, and 9; each 15-20 kb in size) of the genome of alkaliphilic Bacillus sp. C-125 cloned in a lambda phage vector have been determined. Thirteen putative open reading frames (ORFs) were identified in sequenced fragment no. 3 and 11 ORFs were identified in no. 4. Twenty ORFs were also identified in fragment no. 9. All putative ORFs were analyzed in comparison with the BSORF database and non-redundant protein databases. The functions of 5 ORFs in fragment no. 3 and 3 ORFs in fragment no. 4 were suggested by their significant similarities to known proteins in the database. Among the 20 ORFs in fragment no. 9, the functions of 11 ORFs were similarly suggested. Most of the annotated ORFs in the DNA fragments of the genome of alkaliphilic Bacillus sp. C-125 were conserved in the Bacillus subtilis genome. The organization of ORFs in the genome of strain C-125 was found to differ from the order of genes in the chromosome of B. subtilis, although some gene clusters (ydh, yqi, yer, and yts) were conserved as operon units the same as in B. subtilis.