The cleaved amplified polymorphic sequence (CAPS) marker uses a restriction enzyme recognition site resulting from single nucleotide polymorphisms and insertions and deletions on the DNA sequence. This technique does not require expensive equipment, the process is simple, and clear results can be obtained reliably. In this study, Agaricus bisporus cultivars SaeA, SaeDo, SaeHan, SaeYeon, SaeJeong, Dodam, Seolgang, Dahyang, Hogam, and Hadam developed in Korea were discriminated using four CAPS markers. Our results indicated that it is possible to distinguish the ten cultivars and determine the genetic diversity among them.