An RNA detection kit comprising: (i) a single-stranded circular DNA template containing: a sequence of 10 to 30 bases complementary to a first portion of a target RNA; a primer-binding sequence of 7 to 8 bases adjacent to 5′-side thereof; and a sequence complementary to a detection reagent-binding sequence such as a guanine quadruplex-forming sequence; (ii) an oligonucleotide primer containing: a sequence of 8 to 15 bases complementary to a second portion adjacent to the 3′-side of the first portion of the target RNA; and a sequence of 7 to 8 bases adjacent to 3′-side thereof and complementary to the primer-binding sequence of the single-stranded circular DNA template; and (iii) a detection reagent such as a guanine quadruplex-binding reagent; is provided.