The　selective　extraction　of　trace-level　metal　ions　from　unconventional　sources　such　as　wastewaters　is　a　long-standing　challenge,　due　to　the　large　concentration　difference　between　the　target　metal　ions　and　the　interfering　ions　in　the　matrix.　We　show　here　that　an　adsorbent　based　on　crown　ether　functionalized　mesoporous　silica　(MS-C-D)　overcomes　this　limitation　for　selective　sequestration　of　Ag(I)　ion.　This　new　adsorbent　has　hierarchical　structure　with　large　specific　area　and　pore　framework,　which　is　conducive　to　the　selective　adsorption　of　trace　levels　of　Ag(I)　from　a　complex　solution　containing　concentrated　interfered　ions　such　as　Cu(II),　Zn(II)　and　Pb(II)　ions.　The　adsorption　affinity　(b　value　of　1.45)　and　selectivity　coefficient　(distribution　coefficient　KDof　1.50 * 105 mL/g)　of　Ag(I)　by　using　MS-C-D　were　dramatically　higher　than　many　other　reported　adsorbents　(e.g.　an　Ag(I)-ion-imprinted　materials　with　KDof　392 mL/g)　in　literatures.　Furthermore,　the　lower　ion　concentration　corresponded　to　higher　selectivity　for　Ag(I).　The　hierarchically　structure　of　MS-C-D　and　the　rigid　cavity　of　dibenzo-18-crown-6　contributed　to　the　selective　adsorption　of　Ag(I).　The　adsorbent　keeps　high　capacity　(about　39.8 mg/g)　and　selectivity　for　Ag(I)　adsorption　after　three　regeneration　cycles.　This　new　composite　adsorbent　is　promising　in　extracting　trace　levels　of　Ag(I)　from　unconventional　wastewaters　containing　high　concentrations　of　interfered　ions.　©　2016