Following seed germination, seedlings typically develop sufficient leaves to facilitate carbohydrate accumulation through photosynthesis, a stage known as vegetative growth. Throughout the vegetative growth phase, plants respond to external and internal signals that stimulate the initiation of floral primordia in the peripheral region of the shoot apical meristem, rather than leaf primordia. This intricate and orchestrated shift from vegetative to reproductive growth is referred to as floral transition. The upcoming chapter will primarily delve into the molecular mechanisms that govern the regulation of floral transition. First, the research results in Arabidopsis serve as a basis for briefly summarizing the six flowering pathways: age, autonomous, gibberellin(GA), sugar, photoperiod, and vernalization pathways. The following section will discuss the regulation of the photoperiod pathway in rice and soybean. The epigenetic regulation of FLC expression will be presented in the third section. In the last section, the principles and theories of vernalization will be elucidated using Arabidopsis FLC gene and wheat VRN1 gene as case studies. The past research results of vernalization at the metabolic level will be reviewed briefly. The theory of vernalization perception will also be proposed. The role of protein phosphorylation and O-GlcNAc modification in wheat vernalization and the prolonged cold memory and resetting of vernalization requirements will also be summarized in this section.