Abstract: Serial analysis of gene expression （SAGE） is a powerful high-throughput experimental technique that allows rapid， quantitative analysis of global gene expression in eukaryotic organisms. A short sequence taq （10~14 bp），which is defined by an anchoring enzyme site at a fixed distance from polyA tail， contains sufficient information to identify mRNA transcript from which it originates. The taqs are ligated to obtain concatemers that are cloned into a plasmid vector for sequencing. The identification and abundance of mRNA can be observed through bioinformatics and statistical analysis of a given tag. SAGE is not only applied in obtaining global profile of gene expression in a given cell or tissue， but also help identify a set of specific genes to the cellular conditions by comparing the profiles constructed for a pair of cells that are kept at different conditions. This review covers a general introduction of SAGE, its protocol， methodological evolution and applications in parasite biology.

Key words: SAGE, mRNA profile, Parasitology