Abstract: Tight oil reservoir development requires large?scale volume fracturing for effectively producing, so the evaluation of the fracturing response is particularly important. The tubing pressure change characteristics after fracturing have a closely relationship with the fracture network system volume (FNSV) or stimulated reservoir volume (SRV) and the size of the single broken pieces or blocks, which is a practical parameter for the evaluation of fracturing effect. If the reservoir pressure converted from the tubing pressure is close to the equilibrium pressure, the radius of the broken pieces in the SRV is relatively small. Similarly, the less pressure change percentage under the cumulative percentage of produced fluid, the bigger SRV shaped under the same fracturing fluid volume, and the better the fracturing effect is