Climate change triggers and exacerbates more extreme weather events, such as cold stress, drought stress, and heat stress. Among these abiotic stresses, cold stress is one of the major environmental stresses that limits the growth and development of crops and decreases crop productivity. Higher plants respond to cold stress at different levels including physiological modifications, changes in concentrations of metabolites, and genes expression, such as CBFs and CORs. To cope with cold stress, plants have evolved a series of mechanisms that allow them to adapt to cold stress at the physiological, biochemical, and molecular levels. To date, much progress has been achieved in cold sensing and signaling transduction, as a responses to cold stress. In the present chapter, we summarize the recent research progress on the main physiological, biochemical, and molecular mechanisms of crops under cold stress.