Proposes　a　multi-agent　secure　group　communication　architecture　and　corresponding　secure　group　communication　protocols　to　ensure　the　confidentiality,　integrity,　authenticity　and　non-repudiation　of　group　communication　message.　Proposes　three　multi-agent　group　re-keying　protocols　to　ensure　each　agent　to　have　the　latest　group　key.　Extends　the　base　knowledge　query　and　manipulation　language　(KQML)　to　support　multi-agent　group　re-keying　protocols　and　secure　group　communication　protocol.