Background : Monoplegia is the paralysis of a limb. It is commonly caused by an injury to the cerebral cortex, and rarely caused by injury to the internal capsule, brain stem, or spinal cord. Most problems with cerebral cortex is derived from the occlusion of a brain cortex blood vessel due to thrombus or embolus. Objectives : This study is to see if there is a significance in thermal differences of acupoints in diagnosis and treatment of monoplegia on an upper extremity to test the validity of acupuncture and herbal treatment for it. Methods : By using Digital Infrared Thermographic Imaging(DITI), thermal differences$({Delta}T)$ of acupoints on the upper extremity in a patient with monoplegia on the right upper extremity were measured after an attack of the disease. By giving Mangeum-tang(萬金湯) and treating the patient with acupuncture. the temperature changes of the upper extremity were examined through DITI and improvement was observed. Results : Compared with the left arm which suffered no such injury, the right recovered about 80% of sensation, and the grade of monoplegia improved from Grade O to Grade V. Also, the temperatures of right palmar-dorsal hand and the region of Weiguan(外關, Waiguan, TE5) were $1^{circ}C$ and $1.45^{circ}C$ higher than the same left region on admission day, but the thermal differences$({Delta}T)$ narrowed to $0.5^{circ}C$ by the last day. Conclusions : Results suggest that DITI screening is a reliable method of prognosis and that the time required for treatment can be estimated through this method in cases of monoplegia to an upper extremity. Also, progress in treatment is reflected in thermal differences of acupoints of the monoplegic upper extremity in accordance with the theory of meridian. This supports a role for acupuncture and herbal treatment for monoplegia.