Abstract: Based on the key accumulation conditions, such as hydrocarbon source rock, the palaeo-temporary structures and gas migration, as well as the spatial-temporal relationship, there are four important favorable accumulation conditions for coal-type gas in Qaidam Basin. The Jurassic source rock is widely distributed with co-existence of a multiple of depressions. The potential reserve is re-evaluated at 13100×10⁸m³, providing a material basis for large-scale accumulation of coal-type gas. The secondary structures developed in the basin during the key accumulation period, such as ^“basin peripheral palaeo-slope, nose uplift and depression belt^”. The basin peripheral zone is the directive zone for long-term hydrocarbon migration, forming a good background for accumulation. The basement weathering crust, whose reservoir space is based on dual media – fractures an pores, is extensively distributed, free from of influence of buried depth. The hydrocarbon migration and accumulation are in the pattern of ^“vertical migration and accumulation from source-controlled faults and lateral transportation on unconformity surface^”.helpful to a large-scale accumulation of natural gas. The study of hydrocarbon accumulation conditions and abundance law provides a theoretical basis for coal-type gas exploration and develops the new theories on the reservoirs controlled by large-scale basin peripheral palaeo-slope structures. It is proposed that the new important exploration areas should be located above and below the basin peripheral unconformity surface. The Altyn Tagh foothill palaeo-nose uplift and slope should be highlighted as the new belt and zone for exploration. This theory leads to remarkable results in oil and gas exploration. The newly additional controlled and proven natural gas reserves have reached 1104×10⁸m³ in recent years, making new breakthroughs in coal-type gas exploration in Qaidam Basin.