Abstract: Objective Pan-liver dynamic multiple phase enhancement scan could be achieve by using multiple detector spiral CT and pressure injector. But technique and patient factors are necessary to get fine tri-phase enhancement liver scan. Materials and Methods 26 cases of online tri-phase enhancement liver scan data which selected from image server were enrolled to be evaluated subjectively and analyzed CT value. Results Show no dissatisfied evaluation of all cases,100% satisfaction were found at parenchymal and portal vein phase, but it抯 65.4% with arterial phase, arterial phase scan time is the technical difficulty for tri-phase enhancement liver scan, delay time after injection of contrast medium is the key point. Conclusion The study illuminate the factors affecting delay time after injection of contrast medium and present operational countermeasure accordingly.