Current findings show that an appropriate indoor thermal environment in educational buildings benefits both the learning efficiency and the building energy performance. These findings emphasize the importance of providing comfortable indoor thermal conditions within these buildings. However, research on thermal comfort in educational buildings is mainly conducted in developed areas rather than in underdeveloped areas. To fill the gap in the understanding of indoor thermal environments and thermal comfort of university buildings in underdeveloped areas, a field investigation was performed in naturally ventilated university buildings in underdeveloped area (Zunyi) within the hot summer and cold winter zone (HSCW) of China during the wintertime. The influence of non-physical factors (e.g., economic level, past thermal experience and thermal expectation) on thermal comfort is also explored. The results show that due to the poor winter indoor thermal condition, 38.3 % of subjects feel "cool" or "cold". The neutral temperature and the 80% acceptable temperature range are 17.36 ℃ and 14.97-20.69 ℃, respectively, which is lower than that predicted by the PMV-PPD model. The comfortable temperature mean value derived by applying the Griffiths' method is 16.88 ℃. The impact of non-physical factors on thermal comfort is demonstrated by the lower values of both the neutral temperature and the lower limit of 80% acceptable temperature zone, comparing with that in developed area cases of HSCW zone. Therefore, it clarifies that passive strategies can be considered when improving winter indoor thermal environment in naturally ventilated university in Zunyi.