Abstract: Testing related to indoor thermal environment and overall heat transfer coefficient of a building envelope is conducted for several continuous days on a representative historic building in Shanghai and the results are compared with the criterion of standard for building energy efficiency. Meanwhile, the hourly indoor thermal environment during a typical meteorological year is simulated. The results indicate that in the aspect of indoor thermal environment, the applicability of the historic building is poor. It is enlarged on the three aspects: 1) The overall heat transfer coefficient of the building envelope cannot meet the requirement of standard for building energy efficiency; 2) If there is no space heating measures, the indoor temperature will be about 10℃ in the coldest month, which means that the indoor thermal environment is not satisfactory for comfort; 3) If there is no air conditioning in hot summer days, the temperature and relative humidity usually are high and some room temperature can be higher than 33℃ in some days, far beyond comfort zone for human living.