In　this　paper,　we　consider　a　reaction-diffusion　model　of　plankton　allelopathy　with　nonlocal　delays.　Using　an　iterative　technique,　the　global　stability　of　the　positive　steady　state　and　the　semi-trivial　steady　states　of　the　system　is　investigated　under　some　weaker　conditions　than　those　assumed　in　Tian　et　al.　[C.R.　Tian,　L.　Zhang　and　Z.　Ling,　The　stability　of　a　diffusion　model　of　plankton　allelopathy　with　atio-temporal　delays,　Nonlinear　Anal.　RWA　10　(2009)　2036-2046].　We　also　show　that　toxic　substances　and　nonlocal　delays　are　harmless　for　the　stability　of　the　positive　steady　state.　Finally,　some　examples　are　presented　to　verify　our　main　results.　(C)　2011　Published　by　Elsevier　Ltd