To　extract　and　pre-concentrate　ultra-trace　methyl　mercury　(MeHg)　from　natural　water,　a　novel　MeHg　ion　imprinted　silica　microsphere　(MeHg　IISM)　was　designed　and　synthesized　by　using　silica　microspheres　as　a　supporting　material,　the　complex　ion　of　1-pyrrolidinecarbodithioic　acid　and　MeHg　(PDC-CH3Hg+)　as　a　template,　methacrylic　acid　(MAA)　as　a　functional　monomer,　azodiisobutyronitrile　(AIBN)　as　an　initiator,　trimethylolpropane　trimethacrylate　(TMPTM)　as　a　cross-linking　agent　and　ethanol　as　a　solvent.　The　as　prepared　MeHg　IISM　is　easy　to　fabricate　with　low　cost,　and　has　excellent　stability,　specificity　and　adsorption　capacity.　It　can　be　used　to　specifically　extract　and　pre-concentrate　ultra-trace　MeHg　from　natural　water　samples　with　a　recovery　of　92-105%,　a　intraday　relative　standard　deviation　(RSD,　n　=　5)　<5%,　a　inter-day　RSD　(n　=　5)　<7%　and　less　interference　of　other　ions　within　30　min.　The　as　prepared　MeHg　IISM　can　be　repeatedly　used　more　than　50　times　with　a　30　mg　MeHg　per　gram　adsorption　capacity.　Combined　with　ICP-MS,　it　can　be　used　for　the　rapid　and　cost-effective　detection　of　ultra-trace　methyl　mercury　in　natural　water.　The　success　of　this　study　promises　a　valuable　technique　for　rapid,　low-cost　extraction/pre-concentration　and　detection　of　ultra-trace　methyl　mercury　in　aqueous　environments.　©　The　Royal　Society　of　Chemistry　2016.