Abstract: An investigation of dermatitis venenata in the raw wool workshop of a wool spinning factory in Lanzhou is reported. The result shows the incidence of dermatitis venenata is 31.42%,most of which is mild form.The cutaneous lesions are mainly distributed on the face, neck and forearm. The rashes are papules with pick or skin color, and are scattered of concentrated on the contacted area. Patch test with the original wool was done and showed negative result after 72 hours. The author lists five points, considering that the wool is the primary irritant. A suggestion of protection and treatment is put forward.