Abstract: Fossil and present-day rock stresses in the Tabei, Zhongyuan, and the Keerkang Oil Fields have been measured using acoustic emission (AE) technique. It has been found by an analysis of the relationship between known oil/gas distribution and stress state that thepresent sreatest principal stress in the Tabei Oil Field is below the average of the country, and that the stress in producing wells is lower than that in the non-producing wells. Therefore, the magnitude of the current stress may serve as a criterion for distinguishing oilbearing structures, for choosing the parameters of pumping pressure, and for the division of production horizons.