Abstract: With continuous expansion of the area for protected cultivation，how to improve chilling tolerance in cucumber has become one of the major objectives in current cucumber breeding program.In present paper，the advances on the estimation of chilling tolerance，the approaches to improve chilling tolerance in cucumber and the mechanisms of chilling injury，heredity and molecular genetics of chilling tolerance were systemically reviewed. It was necessary to estimate the chilling tolerance in cucumber according to the integration of indexes，such as, the germinating ability under low temperature，the content of MDA and the leakage rate of electrolyte. Cold acclimation，treating with hormones，heating shock and breeding new varieties with chilling tolerance were used to improve chilling tolerance in cucumber，in which the last one was thought to be the most important one. The decrease of fluidity and increase of permeability of cytomembrane，the repression of photosynthesis，the weakening of absorbance in cucumber root，the reduce of soluble sugar content, the accumulation of starch grains and the destroy of stability of microtubules were involved in the mechanisms of chilling injury in cucumber. The germinating ability at low temperature was determined by non-additive genes，while the chilling tolerance was controled in young plants by additive genes. The molecular genetics of chilling tolerance in cucumber was rarely reported，except for an unknown function gene CCR18 which expressed specifically during low temperature acclimation was cloned. The signal transduction system should also been studied in order to further discover the mechanisms of chilling injury，and the trait of stress-tolerance in wild cucumber species should been explored to widen the genetic basis and breed the new varieties with cold tolerance adaptable to protected culture.