cDNAs corresponding to two types of mouse alpha 1-acid glycoproteins (AGPs), Agp-1 and Agp-2, were cloned and sequenced. Two alleles of Agp-1 were also identified from inbred mice by restriction site polymorphisms. One allele, Agp-1A, is associated with AKR/J, SJL/J, and SWR/J mice, while the other, Agp-1B, is found in BALB/c, DBA/2, C57BL/6, B10, and A/J mice. cDNAs of both Agp-1A and Agp-1B were cloned from BALB/c and (B10 x AKR/J)F1 mice. A single nucleotide substitution in the coding sequence of Agp-1 is responsible for the observed difference in electrophoretic mobilities of Agp-1A and Agp-1B. Several additional nucleotide variations in the 3' untranslated region were also found. In contrast to these two alleles, substantial nucleotide difference exist between Agp-1 and Agp-2. Agp-1 and Agp-2 contain five and six potential N-glycosylation sites, respectively.