H5N1 (Avian influenza virus) has caused economic loss and remained a serious human health risk in many countries, including Vietnam. Plant-derived vaccines have offered the advantages over tradition subunit vaccine with low-cost production potential. Duckweed (Sprirodela polyrhiza L.) has found a valuable target plant for various application. In this study, we have attempted to re-generate and transform the gene encoding the hemagglutinin antigen of H5N1 virus in frond of S. polyrhiza, a widely great duckweed grown in Vietnam. The results have shown that the culture medium for S. polyrhiza duckweed is Hutner medium with reduced mineral concentration ½ (H/2) supplemented with 10g/l sucrose at pH 6. This medium showed appropriate for the best growth and development of duckweed. Results of PCR analysis of S. polyrhiza lines from 14 transformation experiments that has obtained 4 duckweed lines carrying HA1 gene. This prelinary results will be provide the basis for transgenic research in the dukweed species and be useful for further generate the producing enable vaccine via the transgenic plants