Abstract: In this paper,some concepts and mithods in the energy flow analyxis of agro-ecosyxtems were discussed.Supplementary energy replace ratio concept was proposed to clrify people s comprehension and understanding to some concepts. It is suggested to replace energy input-output ratiowith supplertientary energy replacement ratio in the energyflow analysis.The calculations of industrial supplementary en-ergy among various systems or at different periods of same system were discussed.