The passive continental margin is a comparatively weak region of plate tectonic movement, but it is a favorable region for gas hydrate. Up to now, more than two thirds of marine gas hydrates are distributed in passive continental margins. Comprehensive study of gas hydrate accumulations in passive continental margins shows that gas hydrate is closely related to fault-fold combination structures, diapiric structures and pockmarks. The bottom simulating reflector (BSR) is the most important indicator for identifying gas hydrates, but it is not a feasible indicator since there is no strict corresponding relationship between gas hydrate and the BSR. There are plentiful gas resources and suitable temperature and pressure conditions for gas hydrate on passive continental margins. Furthermore, fault-fold structures, horst-graben structures and diapiric structures provide favorable tectonic environments for the migration, enrichment and pool-formation of hydrocarbon gases, which will ultimately form gas hydrates in these regions. Multiple superimposed basins are frequently developed in deep-water regions of passive continental margins, and usually a composite hydrocarbon accumulation model is formed in these regions, which is characterized by deep oil, middle gas and shallow gas hydrate because of their internal links in regard to hydrocarbon origin, temperature, pressure, structure and sedimentary conditions.