This study was to present the preferred and the suggested indoor temperature of college students in winter based on their body composition. A total of 14 subjects(6 males and 8 females) participated in this study. They sat in a climatic chamber controlled at $24^{circ}C$ wearing experimental garments(0.7clo). The air temperature decreased $1^{circ}C$ every 15 minutes until it reached $19^{circ}C$. After the stepwise temperature change, subjects were asked to select a comfortable air temperature by dialing the temperature control switch inside the chamber. The preferred temperature was determined when subjects did not change the air temperature for 10 minutes. The measurements were oxygen consumption, rectal temperature, skin temperature, and subjective sensation. Main results are as follows. In a mild cold condition, females demonstrated lower oxygen consumption and mean skin temperature than males while keeping a constant rectal temperature. Females increased rectal temperature and decreased mean skin temperature greater than males from $24^{circ}C$ to $19^{circ}C$. Males showed larger oxygen consumption increase than females. It appears that the thermo-physiological responses in a mild cold condition might be different between males and females. The preferred winter indoor temperature was $22.3^{circ}C$ for males and $23.4^{circ}C$ for females, and the suggested temperature was $21^{circ}C$ for males and $23^{circ}C$ for females.