A framework for estimating the human impedance is proposed in this paper. In physical human-robot interaction (pHRI), safety and human acceptance are key issues when humans directly interact with the robots. In order to guarantee the safety and improve performance in pHRI, it is important to estimate the dynamics and intention of the human hand. In this work, we consider that a human subject physically contacts with a force sensor when a haptic device sets force in the proposed framework. The measured force, the surface electromyographic signal and the motion of the hand are used to estimate the parameters of human forearm’s impedance. The effectiveness of the proposed framework is demonstrated by experimental results.