Quantitative assessment of muscle spasticity is an important issue in the rehabilitation medicine. However, there are a small amount of qualitative and quantitative assessment be used in clinical studies for that the mechanism of vasospasm is not clear yet. The objective of this paper is to suggest a totally new method using independent component analysis (ICA) to analyze spasticity and indicate possibility to apply this method for evaluation of spasticity. In order to simulate the experiment of human swing leg angle bending system, an entry system with the input signal and the original angle had been established. And the system's pulse signal had been reconstructed. By comparing the thigh swing test experiments of healthy people and patients and analyzing their different impulse signals and impulse responses, the index of evaluation of spasticity had been obtained.