A congenic strain of mice with amyloidogenic apolipoprotein A-II (Apoa2c) on the genetic background of the amyloidosis-resistant SAM-R/1 strain was produced by 12 generations of backcrossing. Genome mapping using endogenous murine leukemia proviral markers was done in the congenic strain, termed R1.P1-Apoa2c. We confirmed that only a small region surrounding the apoA-II gene on chromosome 1 was transferred from the genome of the donor SAM-P/1 strain. The level and particle size of plasma high density lipoprotein were decreased in R1.P1-Apoa2c mice compared to those in the progenitor SAM-R/1 mice. The function of apoA-II can be studied using this strain of mice.