The pressure slope calculation of CO₂ foam fracturing fluid in conduit flow was the key to reliability of whole fracturing process，which influenced the effect of formation stimulation. The friction characteristic of CO₂ foam fracturing fluid was investigated at high temperature and pressure by conduit flow experiment which simulated field condition，and the effect of pressure，temperature，foam quality，and flow rate on friction characteristic of CO₂ foam fracturing fluid was analyzed. The mathematic model of friction resistance coefficient was established，and the friction resistance of CO₂ foam fracturing fluid in turbulent flow was predicted. The results showed that the friction resistance coefficient of CO₂ foam fracturing fluid declined with increasing temperature，flow rate and pressure，and increased with increasing foam quality. Once the foam quality exceeded 75%，the friction resistance coefficient would reduce. The effect of pressure on the friction resistance coefficient was not obvious. The calculating result of mathematic model of friction resistance coefficient indicated that CO₂ foam fracturing fluid had viscosity increasing effect on the condition of laminar flow，and that had friction reducing effect on the condition of turbulent flow. On the condition of same delivery rate，the friction resistance of 31/2″ tube was less than that of 27/8″ tube，and 31/2″ tube was usually applied for CO₂ foam fracturing. The investigation on friction characteristic of CO₂ foam fracturing fluid was helpful to design parameters of field fracturing.