Objective To investigate the effects of different degrees of white mustard stir-processing on patient skin after acupoint application. Methods The same production batch of raw white mustard were randomly allocated to groups A, B and C. Fifty asthma patients were received acupiont application. Raw white mustard was stir-processed into slight yellow in group A, deep yellow in group B and coke yellow in group C. the skin reaction was observed in the three groups of patients after acupoint application. Results Obvious skin burning heat and burning pain sensations, and skin redness accompanied by many blisters occurred at the place of application in group A. Skin warming sensation, no or a small amount of needle tip-like blisters and skin redness without edema occurred at the place of application in group B. No or slight skin redness and unobvious skin warming sensation occurred at the place of application in group C. Conclusion White mustard stir-processed into deep yellow can effectively reduce the excessive stimulation of medicine to the skin and not markedly affect the amount of medicamentous stimulation to the acupoint.