We propose a coefficient of friction for quantifying the needle grasp sensation of acupuncture needles applied using the lifting-thrusting method. To measure the force exerted on an acupuncture needle, six tissue specimens of varying hardness were selected and the lifting-thrusting method was applied to the samples using a needle insertion measurement system. The measured values of the force can be expressed as friction coefficients through analysis with a modified Karnopp friction model. Needle grasp was measured using the visual analog scale (VAS). By comparing the coefficients of friction and the VAS values, we determined that the subjective phenomenon of needle grasp can be quantified with Cp (the positive coefficient of the kinetic friction). Objective measurements of changes in sensation can thus be obtained by determining Cp.