Purpose: Cold hypersensitivity is regarded to be associated with blood circulation. This study is aims to evaluate the effects and safety of oxygen chamber therapy on cold hypersensitivity by comparing the temperature and Visual Analogue Scale. Methods: 42 outpatients who visited ${igcirc}{igcirc}$ University Oriental Hospital from July 11th, 2013 to August 28th, 2013 were analyzed. Patients were subjected to thermometer, and those with thermal difference greater than $0.3^{circ}C$ between upper arm and palm and also with more than VAS 4 of cold hypersensitivity were diagnosed with cold hypersensitivity. 42 outpatients diagnosed with cold hypersensitivity are divided into two groups, one is the experimental group consisted of 21 patients and other was control group consisted of 21 patients. The experimental group had oxygen chamber therapy 10 times for 4 weeks. Thereafter the effects of oxygen chamber therapy on cold hypersensitivity was analyzed with t-text using SPSS for Windows version 21. Results: After the oxygen chamber therapy, experimental group had considerable improvement on cold hypersensitivity, in consequence of decreasing rate of thermal difference and VAS of cold hypersensitivity. Ear deafness and hand numbness were reported as an adverse effects in experimental group, but there was no serious adverse effects. Conclusions: This clinical trial showed oxygen chamber therapy could be effective and safe to reduce cold hypersensitivity.