Seed dormancy is an important adaptive mechanism to protect seeds under the unfavorable environments. Unlike to wild type species, the seed dormancy trait of cultivated crops has been weakened by breeding programs during the domestication period. Weak seed dormancy often causes preharvest sprouting (PHS) problem in many cereal crops that result in significant economic loss. The seed dormancy is a quantitative trait loci (QTL) controlled by multiple genetic and environmental factors. So far, many QTLs for seed dormancy have been identified from rice and wheat as well as in the model plant Arabidopsis. Unveiling of QTL genes and complex mechanisms underlying seed dormancy is accelerated by the rapid progress of crop genomics. In the present study, we reviewed current status of research progress on the seed dormancy QTLs and correlated genes in Arabidopsis and cereal crops.