The session on the palaeontology and stratigraphy of South East Asia is introduced by discussing the general tectonostratigraphic structure of South East Asia. The structure of South East Asia is described with respect to its evolution during the Palaeozoic. We introduce the main structural regions in relation to their stratigraphy. Despite superficial resemblances in their geomorphology and composition, the palaeozoic limestones of South East Asia may have very different origins and tectonostraigraphy (Metcalfe 1996). Currently the pre-Tertiary of South-East Asia can be divided into four tectonostratigraphic terrains; these are: the Sibumasu (Burma (Myanmar), north-west Thailand, west Peninsular Malaysia and north-western Sumatra), east Peninsular Malaysia (including south-east Sumatra), Indo-China (east Thailand, Laos, Vietnam and Cambodia), and south-west Borneo. Evidence suggests that all of these terrains had their origin in the IndianAustralian fringes of Gondwana (Metcalfe 1988; Metcalfe 1996).