Abstract:Flowering time (FT) refers to the time from open till closure of lemma and palea in single spikelet. FT synchrony is the most important factor influencing production of hybrid seeds, especially to those potential heterosis combinations between japonica and Indica, due to the japonica CMS’s during flowering. The present review concerned the advances on the flowing characteristics, study methods, genetic, breeding practice, which will benefit to the effort on removing the flowering time asynchronization obstacle and promoting hybrid rice seeds production.