A transformation model for Laminaria japonica was established from 1993 to 1998, on the basis of which the transgenic kelp with heterologous gene encoding hepatitis B surface antigen (HBsAg) was obtained by using the micro-particle bombardment transformation method. Results of quantitative ELISA showed that HBsAg in transgenic kelp was 0.529μg/mg soluble proteins on average and the highest value was 2.497μg/mg, implying that recombinant HBsAg had natural epitope. Further support for the integration of HBsAg gene into kelp genome was obtained by PCR-Southern and total DNA hybridization. Prospect of kelp bio-reactor producing high value materials such as edible HBY vaccine was discussed as well. A transformation model for Laminaria japonica was established from 1993 to 1998, on the basis of which the transgenic kelp with heterologous gene encoding hepatitis B surface antigen (HBsAg) was obtained by using the micro-particle bombardment transformation method. Results of quantitative ELISA showed that HBsAg in transgenic kelp was 0.529 μg / mg soluble proteins on average and the highest value was 2.497 μg / mg, implying that recombinant HBsAg had natural epitope. Further support for the integration of HBsAg gene into kelp genome was obtained by PCR-Southern and total Prospect of kelp bio-reactor producing high value materials such as edible HBY vaccine was discussed as well.