A 2′-deoxyribonucleoside is produced by culturing a microorganism, which is transformed with a gene encoding a ribonucleotide reductase and in which 2′-deoxyribonucleoside degradation activity is decreased or eliminated by disrupting a gene encoding a purine nucleoside phosphorylase on chromosomal DNA, in a medium in which the microorganism can grow to produce the 2′-deoxyribonucleoside.