This paper addresses sensory evaluation of cutting force for an encountered-type haptic interface using MR fluid. The encountered-type of haptic interface using MR fluid can display arbitrary force by controlling the magnitude of yield stress of MR fluid and an operator can feel resistance force by cutting the MR fluid directly with surgical instrument. In the previous studies, we tried to reproduce cutting force of authentic biological tissue, swine liver, by this haptic interface. However, we discovered that an operator did not feel same cutting force as in cutting the real swine liver even though the haptic interface reproduced the cutting force of real swine liver. Therefore, this paper carries out sensory evaluation of cutting force to clarify dominant factors of the cutting sensation and discusses how different between the real swine liver cutting and reproduced cutting force by the haptic interface. Then, we discuss possible improvement of the system for precisely reproducing the cutting sensation.