The　paper　describes　the　application　of　biological　theory　to　an　eco-industrial　park　(EIP),　and　provides　support　to　some　earlier　research.　Natural　ecological　theory　is　applied　to　the　development　of　two　indices　by　which　to　evaluate　an　EIP.　The　first　index　is　the　eco-connectance　of　an　EIP　that　defines　the　degree　of　the　connectivity　among　the　enterprises　or　factories　in　an　EIP;　the　second　index　defines　the　degree　of　byproduct　and　waste　recycling　in　an　EIP.　The　eco-connectances　and　the　byproduct　and　waste　recycling　rates　of　selected　ElPs　were　analyzed　with　the　aid　of　theories　that　are　proposed　in　the　paper,　and　corresponding　measures　are　put　forward　for　planning　and　building　of　ElPs　in　the　future.　(C)　2009　Elsevier　B.V.　All　rights　reserved.