Abstract: Horizontal wells are adopted to exploit marine carbonate gas reservoirs with high H2S content in Puguang area. To determine the appropriate completion method and later stage stimulation measures for horizontal wells in sour gas fields in Puguang area, in-situ stress field of marine reservoir layers should be precisely gained at first. Imaging logging data of 16 wells was used to determine the horizontal maximum stress direction, and statistical results indicated that the horizontal maximum principle stress extended nearly east-westward. Combined density logging with cross-dipole acoustic logging data based on the relationship between rock strength and acoustic slowness, rock mechanical parameters of marine reservoir mainly layers in Puguang were calculated. Layered earth stress calculation model combined with imaging logging data and well stability information during drilling were used to calculate the magnitude of in-situ stress of marine reservoir. These results can instruct the development scheme for marine carbonate gas reservoirs in Northeast Sichuan.