Dielectric　response　characteristics　of　transformer　oil-paper　insulation　system　can　be　described　using　extended　equivalent　circuit　of　the　Debye　model.　Study　on　extended　Debye　model　equivalent　circuit　parameter　identification　method　of　oil-paper　insulation　system　is　of　great　significance.　This　paper　proposes　a　method　using　polarization　current　curve　to　identify　extended　Debye　equivalent　circuit　parameters　of　oil-paper　insulation　transformer.　Because　the　terminal　of　polarization　current　curve　depends　on　the　large　time　constant　exponential,　so　firstly,　it　can　take　the　points　at　the　end　of　the　curve　to　calculate　estimated　values　of　the　parameters,　to　modify　the　calculation　based　on　estimated　values　to　get　accurate　values,　then　check　the　calculation　to　obtain　more　accurate　values.　One　branch　respectively,　all　polarization　branch　parameters　can　be　obtained.　Using　this　method,　the　equivalent　circuit　parameters　of　several　transformers　are　identified.　The　calculated　equivalent　circuit　parameters　are　accurate　and　polarization　current　curves　fitting　good,　the　feasibility　of　this　method　is　verified.　©　2016,　Xi＇an　High　Voltage　Apparatus　Research　Institute　Co.,　Ltd.　All　right　reserved.