Some Permian and Carboniferous ammonoids have been collected from Lampang, Loei,
 and Sop Pong areas of northern Thailand.  The ammonoids of Lampang area indicate the
 uppermost Permian (Dorashamian), and those of the latter two areas indicate Lower
 Pennsylvanian.  Nine species of seven genera of the uppermost Permian ammonoids are
 found in the collected specimens from Lampang area at present as follows; Prototoceras sp.,
 Paratirolites aff. spinosus, Pseudogastrioceras aff. szechuanense, Pseudotirolites sp.,
 Tapashanites floriformis, T. changxingensis, Tapashanites (?) sp., Huananoceras (?) sp., and
 Xenodiscus sp.
     Lower Pennsylvanian ammonoids consists of Pseudoparalegoceras sp., Gastrioceras sp.
 A, Gastrioceras sp.  B, Branneroceras (?) sp., Paralegoceras sp., and Cravenoceras (?) sp. occur
 in the Wang Saphung Formation, distributed around Loei City, Loei area, and two species of
 Carboniferous ammonoids, Pronorites arkansasensis and Cravenoceras (?) sp. have been
 collected in Sop Pong area.
     All species of ammonoids except Pseudogastrioceras aff. szechuanse, Tapashanites (?) sp.,
 and Xenodiscus sp. are described for the first time in Thailand.  The Paleozoic ammonoids
 have been reported from restricted regions in Thailand until now, and these ammonoids
 described in this paper are very precious and important for the paleontological and
 biostratigraphical studies not only in Thailand but in Southeast Asia.