Molecular and cellular processes related to the senescence syndrome are determined by programs of differential gene expression. Subtractive cDNA hybridization is a powerful approach to identify and isolate differentially expressed genes in various systems. A highly effective method, termed suppression subtractive hybridization (SSH), has been applied for the generation of subtracted cDNA library of senescing leaves. The method consists of two main stages, the normalization step that equalizes the abundance of cDNAs within the target population and the subtraction step that eliminates the common sequences between the target and the driver populations. The successful generation of library containing high numbered of rare and abundant cDNA clones in senescing plant cells proves the applicability of this method for global identification of differentially expressed genes during cellular senescence.