A novel drought-response transcription factor gene PeDREB2b cloned from Populus euphratica Oliv. was successfully transferred into white clover (Trifolium repens L.) 'Hai Fa' by soaking seeds with Agrobacterium tumefaciens. In total, 52 kanamycin-resistant primary transformants were obtained. PCR analysis confirmed that 6 of them carry the PeDREB2b gene. Southern blotting and GUS assay confirmed that that the PeDREB2b gene had been integrated into the plant genome. The transformation efficiency was 0.96%, calculated on the basis of the total number of the germinated seeds. The transgenic plants showed significant stronger drought-tolerance than non-transgenic plants. Our research suggested that the transformation method of soaking seeds with A. tumefaciens is effective for white clover and PeDREB2b can be used as an approach to enhance drought tolerance in white clover.