Seaweed research at the Aquaculture Department of SEAFDEC focuses mainly on 2 genera of agarophytes (Gracilaria and Gracilariopsis) and carrageenophytes (Eucheuma and Kappaphycus). From 1988 to 1998, research works were mainly on Gracilaria and Gracilariopsis along these areas: (1) refinement of culture technique, (2) basic biology, production ecology, and corp management, (3) product utilization, (4) screening and characterization of natural products, and (5) economics of farming system. Four years ago, the Seaweed Program of the Department re-focused its thrust on Advanced Aquaculture Technologies (Biotechnology) to include also Eucheuma and Kappaphycus in answer to the needs of the industry. This paper briefly describes the highlights of the different studies done on biotechnology.