Based on the analysis of the geological conditions of hydrocarbon accumulation in the southern Songliao Basin, the present fluid potential of Gaotaizi reservoir is calculated and the palaeo-fluid potential is recovered with the hydrocarbon accumulation dynamics systematic research as the core. The results show that the palaeo-present fluid potential of Gaotaizi reservoir is always high in the belt of Daan Depression-Changling Depression. Applying the hydrocarbon accumulation dynamic system analysis results, combined with tectonic sedimentary evolution and reservoir fluid inclusion studies, the hydrocarbon charging and accumulation in the Gaotaizi reservoir is characterized.