Abstract:cDNA microarray method was employed to study genes expression pattern in Tamarix androssowii under drought stress. cDNAs from T.androssowii treated with drought stress and control group were labeled with two fluorescence dyestuff Cy5 and Cy3,and hybridize with cDNA microarray containing T.androssowii genes. Gene expression under drought stress was studied through scanning and analysis of gene chip by computer. Totally 47 down-regulated genes and 62 up-regulated genes were obtained. Blastx analysis showed that the function of these genes could be grouped into the categorizations such as dehydration protection,signal transduction and regulation,active oxygen scavenging,photosynthesis,metabolism,ribosomal protein,and protein breakdown and recycling. At the same time,some function unknown genes and new genes related to drought stress were also found. This research revealed some important pathways of drought-resistance in T.androssowii,such as active oxygen scavenging,regulation of metabolism,dehydration protection and protein breakdown and recycling.In addition,the differential expression of genes in T.androssowii before and after drought stress were also elucidated.