The stress field of the bottom of the First Member of the Shahejie Formation in the central part of Huanghua Depression in Bobai Bay Basin was analyzed by applying finite element computer simulation.According to its distribution characteristics

its property and the relation between the stress field and gas enrichment

it is suggested that the environment of weak extension and strong shearing stress is favourable for natural gas accumulation.It has been proved that bigger gas fields in the Bobai Bay Basin are almost associated with compressoshear stress environment.The main cause for this is that the environment is beneficial for natural gas generation and expulsion

and it is also favorable to form good sealing traps.