Abstract:Cytokinins are important plant hormones and can delay plant senescence, In this review three approaches in study of the effects of cytokinins on plant senecence are presented： the analysis of endogenous cytokinins during senescence； the application of exogenous cytokinins； and the research on transgenic plants with cytokinin biosynthesis or biodegradation genes. The mechanisms of cytokinins in retarding of senescence was discussed in relation to saccharides, lipid oxidation, as well as to other hormones.