Well Su 75-70-6H is the largest open hole horizontal well fracturing built by domestic technologies. Orientation of horizontal section is north-south. Microseismic monitoring shows whether fractures are generated, locations and patterns of fractures, and further provides a guide for fracturing operations; monitoring can also identify location of possible fracturing fluid leakage, provide early warning of sand blocking and help evaluate the effectiveness of stimulation. It proves that domestic manufactured fracturing downhole tools can be used.The result of microseismic monitoring accuratly reflect the operation process, as well as guide it.