Abstract: Based of the ersearch of carbonate-type oil/gas source rocks from lower Permain in Xi-chang Basin, lower Ordovician in Ordos Basin，and lower Carboniferous in Majiaoba,Jiangy-ou, the author in this paper finds that organic inclusions could be formed in deck stage of the thermal evolution of oil/gas source rocks. Organic inclusions are the primary samples for hy-
drocarbon matter in oil/gas source rocks，and thus embody all sorts of events and informa-tion associated with hydrocarbon matter occurring in the thermal evolution of carbonate一type oil or gas source rocks. Therefore，in the evolution of oil/gas souce rocks，the inclusion's types，characteristics，paleo一temperature，quantity,composition, and some oth-er parameters will offer an effective approach towards the study of (1) the thermal evolution
degree and matueity stage of oil/gas source rocks;(2) sedimentary basin paleo一tenperature and the thermal evolution history of oil source rocks;(3) the regional distribution and divi-sion of organic matter maturity in oil/gas rocks;(4) assessment.of oil/gas resource abun-dance;and (5) the nature and origination of oil/gas source rocks.

Key words: Organic inclusions Carbonate rocks Oil/gas sourc