Because　there　was　no　suggestion　value　of　period　shortening　factor　of　concrete　frames　with　buckling-restrained　brace　(BRB)　in　chinese　code,　the　authors　researched　48　different　cases,　with　the　consideration　of　infill　wall＇s　nonlinear　performance　to　find　the　proper　value　of　period　shortening　factor　for　different　seismic　design　requirements.　The　conclusion　is　that　the　period　shortening　factor　relates　to　the　displacement　requirement　of　seismic　structure　and　the　influence　of　structural　system　to　the　period　reduction　factor　is　not　obvious.　Finally,　the　authors　gave　the　suggested　values　of　period　reduction　factor　for　concrete　frame　with　BRB.