The　difficulty　in　landfill　leachate　treatment　is　probably　attributed　to　high　content　of　humic-like　matter.　The　concentration　of　humic-like　matter　as　a　function　of　landfill　age　was　established.　The　parameters　were　determined　using　the　data　from　the　leachate　treatment　facilities　by　means　of　grid　method　and　solving　non-linear　eqations　using　Newton　iteration　method.　Meanwhile,　the　accuracy　of　this　prediction　model　was　testified　by　comparing　with　residual　COD　values　of　biologically　treated　leachate　both　from　the　test　and　the　monitoring　data　in　site.　The　modeling　results　showed　that　the　concentration　of　humic-like　matter　increased　first　and　then　decreased　with　the　increase　of　landfill　age,　and　indicated　that　biological　processes　generally　cannot　reduce　the　COD　sufficiently　to　be　allowed　direct　discharge　during　the　major　part　of　whole　period　of　landfill　stabilization.　Thus　it　could　provide　basis　for　humic　acid　recycling　from　leachate　and　guidance　in　selection　of　treatment　processes　for　leachate.　©　2011　IEEE.