The　methane　emission　in　a　loess-gravel　capillary　barrier　cover　(CBC)　in　winter　and　summer　was　investigated　by　constructing　a　full-scale　testing　facility　(20　m　×　30　m)　with　a　slope　angle　of　14.5°　at　a　landfill　in　Xi＇an,　China.　Weather　conditions,　methane　emission,　gas　concentration,　temperature,　and　volumetric　water　content　(VWC)　in　the　CBC　were　measured.　The　temperature　and　moisture　in　the　CBC　showed　a　typical　seasonal　pattern　of　warm　and　dry　in　summer　and　cold　and　wet　in　winter.　Accordingly,　the　maximum　methane　oxidation　rate　and　methane　emission　were　higher　in　summer.　The　mean　methane　influx　and　methane　emission　decreased　significantly　as　the　VWC　increased　beyond　40%　(i.e.,　a　degree　of　saturation　0.85)　at　a　depth　of　0.85　m,　which　was　near　the　loess/gravel　interface.　At　this　depth,　more　water　was　presented　in　the　loess　layer　in　the　downslope　direction　due　to　capillary　barrier　effects,　which　increased　the　upslope　methane　emission.　More　dominant　methane　emission　in　the　middle-　and　upper-section　of　the　CBC　occurred　in　summer　than　in　winter　as　there　was　less　soil　moisture　to　facilitate　methane　transfer.　The　LFG　balance　showed　that　a　significant　fraction　of　the　loaded　LFG　was　not　accounted　in　the　flux　chamber　measurements　due　to　the　preferential　flow　along　the　edges　of　the　CBC.　The　maximum　methane　oxidation　rate　was　93.3　g　CH4　m−2　d−1,　indicating　the　loess-gravel　CBC　could　mitigate　methane　emissions　after　landfill　closure.　©　2020