Based on the observations and extremes of temperature and relative humidity of automatic weather station type 2(AWS Ⅱ) and conventional observation station during January 2001 through April 2002, their statistical results are given. It is shown that owing to systematical error of observed instrument and time difference in observation, mean daily temperature of automatic weather station is 0 2℃ lower than that of conventional observation station, mean daily relative humidity is 2% higher than that. The difference of extremes of temperature and relative humidity exists nonlinear variation. Monthly minimum temperature exists positive value change for minimum temperature being over 8℃,exists negative value change for that below 8℃. Most of the difference of extremes of monthly maximum temperature exists negative value change, which in summer is more obviously than that in other seasons. The difference of minimum monthly relative humidity with <35% appears instability but positive value change with ≥35%.