Cold adaptation is one of the most important functions for the human. In this study we focused on its relationship to mitochondria. The mitochondrion itself exists in human cells and has a vital function in generating ATP and heat. Mitochondria have their own genome, which enables modern humans to classify the mitochondria haplogroup. Recent studies have suggested that these haplogroups were shaped by climatic change and the mitochondrial genome influence balance between ATP and heat generation. In this study we hypothesized that human cold adaptability is influenced by the mitochondrial haplogroup. Our purpose was to investigate the association between mitochondrial haplogroup and psychophysiological responses during cold exposure. We focus on haplogroup D, the biggest group in Japan and also a major group in northern Asia, including Siberia. Subjects were 18 young Japanese university students divided into two groups: the D group and the non-D group. There was no significant difference of height, weight, BMI, or BSA between them. Cold exposure was induced for 90 minutes in a climatic chamber; for the first 30 minutes, the air temperature was decreased from 27℃ to 10℃ and, for the last 60 minutes, the temperature was maintained at 10℃. Rectal and skin temperatures, oxygen consumption (VO2), blood pressure, and thermal comfortability were measured during the experiment. The result showed that the D group had significantly higher Tre during cold exposure (p<0.001), with no significant difference in VO2 and mean skin temperature. This suggests that mitochondrial haplogroup D is associated with cold resistance and haplogroup.