Abstract: During open-hole staged fracturing operation in horizontal wells of Daniudi Gas Field and Honghe Oilfield in the Erdos Basin, there were challenges such as the separation of long horizontal sections in one trip, the development of natural fractures and ineffective isolation due to hole enlargement.Considering the geological conditions, well trajectory and hole diameter changes in both fields, the staged fracturing tools with multi-stage sleeves for open hole in horizontal wells were developed and relevant operation techniques were established.The tools were applied in more than 20 wells in the Erdos Basin with totally 200 stages fractured.Field applications achieved good results, including the smooth running of the completion string of the staged fracturing tools with multi-stage sleeve for open hole in horizontal wells, effective sealing of packer, sleeve opening with high success rate, and dramatic increase of production after fracturing.These proved that these tools could solve the problems that occurred in open hole staged fracturing operations in Daniudi Gas Field and Honghe Oilfield, and are appropriate for intensive application in the Erdos Basin.