The short-chain dehydrogenases/reductases (SDRs) play important roles in body's metabolism. We cloned a novel mouse SDR cDNA which encodes a deduced HSD-like protein with a conserved SDR domain and a SCP2 domain. The 1.8 kb cDNA consists of 11 exons and is mapped to mouse chromosome 4B3. The corresponding gene is widely expressed in normal mouse tissues and its expression level in liver increases after inducement with cholesterol food. The predicted mouse HSDL2 protein, which has a peroxisomal target signal, is localized in the cytoplasm of NIH 3T3 cells.