HIV-1　integrase　(IN)　is　essential　for　the　replication　of　HIV-1　in　human　cells.　At　present,　the　complete　structure　of　complex　IN-DNA　has　not　been　resolved.　In　this　paper,　a　HIV-1　IN　tetramer　model　was　built　with　homology　modeling　and　molecular　dynamics　simulation　approach,　in　which　two　Mg2+　ions　were　reasonably　located　in　each　catalytic　core　domain.　Moreover,　it　was　found　that　the　AB　and　CD　chains　of　HIV-1　IN　tetramer　were　different　in　the　structures　and　metal　ions　of　HIV-1　IN　tetramer　might　have　great　influences　on　DNA　locating　on　IN.　These　findings　may　provide　a　more　complete　structural　basis　for　guiding　drug　discovery　and　revealing　integration　mechanism.　(c)　2005　Elsevier　Inc.　All　rights　reserved.