Abstract: A dynamic modeling of the upper limb wrist joints was studied to understand the movement characteristics of the wrist in and out of the wrist in this paper. The system delay concept was introduced with human autonomous control and to simulate the sensory delay characteristics of Parkinson's patients.The stability analysis and numerical solution of this time-delayed control system showed that, when the sensation is delayed to a certain extent, resting tremor would happen if patients with Parkinson's wrist in resting or slow motion . From the analysis in this paper, we can infer that Parkinson's disease resting tremor is caused by sensation and movement delay.