The λ-type structure is one of shear-form.The authors

proceeding from astudy of some oil-bearing λ-type structures such as Zhongba

Sichuan

elucidate the characteristics of oil and gas distribution in the λ-type structure

analysethe tectonic stress field of the λ-type structure in connection with photo-elastic experiments

discuss the effects of the stress activity on the migration and accumulation of oil and gas and the inner cause of controls

analyse the fundamental geological conditions for the formation of the oil-bearing λ-typestructure

and approach the controlling effects of the λ-type structure onthe distribution of oil and gas.In this paper an attempt is made to furtherre flect the major features of the control on oil and gas by the shear structure from such an aspect as the λ-type structure.