In order to study the effect of meteorological parameters on human comfort, the probability distribution, interannual variation, and intermonthly variation of human comfortability in Nanjing, and the relationship between meteorological parameters and PET hysiological equivalent temperature) are analyzed by means of the MEMI (Munich Energy balance Model for Individuals) model. The results show that: (1) the occurrence probabilities of various thermal perception classes vary greatly, and there are fluctuations in the interannual distribution of human comfortability and evident difference in the intermonthly distribution. (2) PET shows a linear growth with increasing temperature, and the increasing rate is the biggest when wind velocity is 1 m/s in cloudy weather; (3) PET also exhibits a linear growth with increasing mean radiant temperature, and the increasing rate is the biggest when temperature is high (25 to 40 ℃); (4) there is a nonlinear decreasing relationship between PET and wind velocity, and the decrease rate, decreasing gradually with increasing wind velocity, is bigger in cold weather and the least in hot and overcast weather. (5) PET increases with increasing relative humidity evidently in hot weather.