The thermal environmental characteristics are experim-entally studied in terms of different air supply volumes and outdoor meteorological parameters in a large-space building which is air conditioned with a low sidewall air supply.The experimental results show that the indoor vertical temperature distributions under different condition are similar.The maximum vertical temperature difference(MVTD)is up to about 20 ℃,and it linearly changes with the sol-air temperature.The indoor vertical temperature gradients(VTGs)in the upper,central and lower zones are different.The influence of the sol-air temperature on the VTGs in the upper and the lower zones is greater than that in the central zone.The characteristics of the VTGs in the three zones affected by the air supply volume are the same as those affected by the sol-air temperature.Besides,because of the small air velocity,the predicted mean vote(PMV)on comfort in the occupied zone is slightly high and the air temperature difference between the head and the ankle is usually more than 3 ℃.