-He thong Cooc-di-e o Bac Mi:dai khoang 9000 km, gom nhieu day nui chay song song voi nhau, rong tu 300-400km .Do cao trung binh tu 3000-4000m.Xen giua cac day nui la cac son nguyen vaq cao nguyen.La khu vuc do so va hiem tro.Co nhieu khoang san:dong, vang ,uranium,quang da kim,.... -He thong nui tre An-det o Nam Mi:do cao trung binh tu 3000-5000m, co dinh len toi 6000m, bang tuyet phu quanh nam .Xen giua la cac thung lung va cao nguyen(cao nguyen TrungAn-det).Chay dai qua nhieu vi do nen thien nhien An-det thay doi tu Bac-Nam,tu thap-cao.
