Abstract: When fracturing low permeability and pressure reservoirs in middle-deep wells in Xinjiang oll field, it requires that the fracturing fluid must posses good heat stabili-ty, meanwhlle, the fi1ter 1oss, residue and damage must be low, guar gum breaking after construction must be complete, and the return of it must be successful. Therefore, chooses hydroxypropylguar gum powder which contaminates reservoir less and is with low residue as the thickener, adds effective emulsifier, cleanup additive and so on into it, and forms the emulsion fracturlng fluid which takes hydroxypropylguar gum as continuous external phase and takes crude oil as internal phase. The property of the emulsion fracturing fluid is superi-or to the standard issued by CNPC. During 1992~1997, the emulsion fracturing fluid was used in oil fields such as Cainan, Xiazijie, Tuha and so on for more than 350 times(200 times in Cainann oil field), the technological success rate is 100%, effective rate is 90%, re-turn rate is more than 95%, average daily incremental oil is more than 12 t, obvious fractur-ing effect is achieved, therefore, the application prospect of this kind of fracturing fluid is broad.