Abstract: Sourceless micorseismic technique is used to monitor fractures in reservoirs. Fracture development patterns in the lower Ⅶ unit in Jianghe block, Shuanghe oilfield are studied in respects of fracture distribution, fracture orientation and direction of terrestrial stress. Fracture study results are used in flood pattern modification, dynamic allocation and improvement of waterflooding effects in the lower Ⅶ unit.