The ds cDNAs were synthesized and enriched by using the 'SMART' method based on the Erianthus arundinaceus treated with drought stress,and separated to the different fragments according to sizes in electrophoresis,then join the T vector and transform the ultra-competent cell of E.coli respectively,so achieve the construction of the Full-length cDNA library,which would redound to the research of anti-drought genes of E.arundinaceus.