Abstract: The difference of atmospheric temperature and humidity profiles derived from MP-3000A microwave radiometer and L-band sounding in Shapingba, Chongqing is compared. Results indicate that: (1) There is a significant positive correlation between microwave radiometer and L-band sounding air temperature over the whole sounding height, and the correlation is higher in lower than in upper. The average temperature deviation is less in 08:00 BT than in 20:00 BT, especially in sun condition it is the least. The temperature is higher by microwave radiometer than L-band sounding, especially in rain condition. (2) The correlation of relative humidity is higher than atmospheric temperature by microwave radiometer and sounding, and less in 08:00 BT than in 20:00 BT below 5 km, but it is basically the same at the two times above 5 km. The relative humidity of the microwave radiometer inversion is larger than that of the upper layers. In rain condition, the detection distortion on rainy days is more obvious because of water vapor, which is attached to the microwave radiometer's radome. It has a great influence on the precision of microwave radiometer inversion. The deviation of relative humidity has the smallest bias in sun condition, followed by in cloud condition.