An immunoregulator that is safe and efficiently incorporated into cells along with a production process thereof are provided. Double-stranded RNA derived from lactic acid bacteria, an immunoregulator having for an active ingredient thereof double-stranded RNA derived from lactic acid bacteria, and a process for producing double-stranded RNA derived from lactic acid bacteria are provided. Bacteria cells of a strains of lactic acid bacteria such as genus Tetragenococcus, genus Pediococcus, genus Lactobacillus, genus Streptococcus or genus Leuconostoc are able to produce double-stranded RNA having immunoregulatory action therein.